DDR SDRAM: Wikis

  

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Generic DDR-266 Memory in the 184pin DIMM form
Corsair DDR-400 Memory with heat spreaders
.Double Data Rate synchronous dynamic random access memory (or also known as DDR SDRAM) is a class of memory integrated circuits used in computers.^ Talking about DDR memory, it is a Double Data Rate.
  • DDR: Ensuring high-speed recovery of data | MULTILNBDISH 10 February 2010 13:54 UTC www.multilnbdish.com [Source type: General]

^ DDR RAM, a shortened version of "DDR SDRAM," stands for "Double Data Rate Random Access Memory."
  • Tag: Ddr - Explore content tagged Ddr on eHow.com 10 February 2010 13:54 UTC www.ehow.com [Source type: General]

^ The DDR SDRAM is an enhanced version of the old school SD RAM. Known as double data rate synchronous dynamic random access memory this chip has a much greater bandwidth to offer to its users.
  • 400mhz 184 Pin DDR SDRAM Desktop Memory | Desktop Memory - The Best Memory Solution for Your Desktop PC 10 February 2010 13:54 UTC desktopmemory.info [Source type: General]

.Compared to the preceding single data rate (SDR) SDRAM, the DDR SDRAM interface makes higher transfer rates possible by more strict control of the timing of the electrical data and clock signals.^ DDR SDRAM (double data-rate SDRAM).
  • ddr sdram | Tags | ComputerWeekly.com 10 February 2010 13:54 UTC www.computerweekly.com [Source type: General]

^ The transfer of data for DDR components can be performed at both edges of the clock signal.
  • Memory Information.com - What is DDR Memory? 10 February 2010 13:54 UTC www.memoryinformation.com [Source type: FILTERED WITH BAYES]

^ Depending on the application, DDR custom interface can be used as a SDR or DDR SDRAM controller.
  • DDR - www.einfochips.com 10 February 2010 13:54 UTC www.einfochips.com [Source type: Reference]

.Implementations often have to use schemes such as phase-locked loops and self-calibration to reach the required timing accuracy.^ Using ODT, DDR3 are able to reduce the parts count required for mother board while at the same time locate the terminations closer the the signal destination.
  • DDR3 DIMM Memory Module Manufacturers and Description, Double Data Rate Memory, DDR III 10 February 2010 13:54 UTC www.interfacebus.com [Source type: Reference]

^ The device has clock speeds of 100, 133, and 166 MHz, phase-lock loop, and bidirectional data strobes.
  • 2-gigabyte DDR SDRAM for high-bandwidth memory systems applications - Military & Aerospace Electronics 10 February 2010 13:54 UTC mae.pennnet.com [Source type: General]

^ It as gold leads and a phase lock loop that helps the clock driver to reduce the loading.
  • 400mhz 184 Pin DDR SDRAM Desktop Memory | Desktop Memory - The Best Memory Solution for Your Desktop PC 10 February 2010 13:54 UTC desktopmemory.info [Source type: General]

[1] .[2]The interface uses double pumping (transferring data on both the rising and falling edges of the clock signal) to lower the clock frequency.^ DDR Double data rate is a type of SDRAM in which data is sent on both the rising and falling edges of clock cycles in a data burst.
  • Apple - Support - Discussions - DDR or DDR SDRAM ... 10 February 2010 13:54 UTC discussions.apple.com [Source type: General]

^ The transfer of data for DDR components can be performed at both edges of the clock signal.
  • Memory Information.com - What is DDR Memory? 10 February 2010 13:54 UTC www.memoryinformation.com [Source type: FILTERED WITH BAYES]

^ It achieves greater bandwidth than the preceding single-data-rate SDRAM by transferring data on the rising and falling edges of the clock signal (double pumped).
  • DDR, DDR2 and DDR3 SDRAM memory modules 10 February 2010 13:54 UTC www.valuemedia.co.uk [Source type: General]
  • DDR 400Mhz, PC3200 SDRAM memory modules 10 February 2010 13:54 UTC www.valuemedia.co.uk [Source type: General]

.One advantage of keeping the clock frequency down is that it reduces the signal integrity requirements on the circuit board connecting the memory to the controller.^ Using ODT, DDR3 are able to reduce the parts count required for mother board while at the same time locate the terminations closer the the signal destination.
  • DDR3 DIMM Memory Module Manufacturers and Description, Double Data Rate Memory, DDR III 10 February 2010 13:54 UTC www.interfacebus.com [Source type: Reference]

^ Type of RAM memory derived from SDRAM where two data are transferred per clock cycle instead of only one.

^ The thing that makes this memory integrated circuit different is that it unlike the other circuits it transfers the data on both the rising and falling edges of the clock signal.
  • 400mhz 184 Pin DDR SDRAM Desktop Memory | Desktop Memory - The Best Memory Solution for Your Desktop PC 10 February 2010 13:54 UTC desktopmemory.info [Source type: General]

.The name "double data rate" refers to the fact that a DDR SDRAM with a certain clock frequency achieves nearly twice the bandwidth of a single data rate (SDR) SDRAM running at the same clock frequency, due to this double pumping.^ Talking about DDR memory, it is a Double Data Rate.
  • DDR: Ensuring high-speed recovery of data | MULTILNBDISH 10 February 2010 13:54 UTC www.multilnbdish.com [Source type: General]

^ DDR SDRAM (double data-rate SDRAM).
  • ddr sdram | Tags | ComputerWeekly.com 10 February 2010 13:54 UTC www.computerweekly.com [Source type: General]

^ Therefore PC2100 DIMMs run at 266MHz, which has a peak bandwidth 2100MB/s, or twice the memory bandwidth of single data rate (133MHz SDRAM).
  • 256MB PC2100 DDR SDRAM - PC World Pricing 10 February 2010 13:54 UTC www.pcworld.com [Source type: General]

.With data being transferred 64 bits at a time, DDR SDRAM gives a transfer rate of (memory bus clock rate) x 2 (for dual rate) × 64 (number of bits transferred) / 8 (number of bits/byte).^ Talking about DDR memory, it is a Double Data Rate.
  • DDR: Ensuring high-speed recovery of data | MULTILNBDISH 10 February 2010 13:54 UTC www.multilnbdish.com [Source type: General]

^ DDR SDRAM (double data-rate SDRAM).
  • ddr sdram | Tags | ComputerWeekly.com 10 February 2010 13:54 UTC www.computerweekly.com [Source type: General]

^ DDR SDRAM DDR (double data rate) memory is the next generation SDRAM. Like SDRAM, DDR is synchronous with the system clock.

.Thus, with a bus frequency of 100 MHz, DDR SDRAM gives a maximum transfer rate of 1600 MB/s.^ DDR SDRAM (double data-rate SDRAM).
  • ddr sdram | Tags | ComputerWeekly.com 10 February 2010 13:54 UTC www.computerweekly.com [Source type: General]

^ Thus, a system with a 100 MHz front side bus has an effective clock rate of 200 MHz when DDR SDRAM memory is installed.
  • DDR, DDR2 and DDR3 SDRAM memory modules 10 February 2010 13:54 UTC www.valuemedia.co.uk [Source type: General]
  • DDR 400Mhz, PC3200 SDRAM memory modules 10 February 2010 13:54 UTC www.valuemedia.co.uk [Source type: General]

^ MHz DDR SDRAM in next eMac?
  • 333MHz DDR SDRAM in next eMac? - AppleInsider 10 February 2010 13:54 UTC forums.appleinsider.com [Source type: FILTERED WITH BAYES]

"Beginning in 1996 and concluding in June 2000, JEDEC developed the DDR (Double Data Rate) SDRAM specification (JESD79)."[3] JEDEC has set standards for data rates of DDR SDRAM, divided into two parts. .The first specification is for memory chips, and the second is for memory modules.^ JEDEC has set standards for speeds of DDR SDRAM, divided into two parts: The first specification is for memory chips and the second is for memory modules.
  • DDR Memory, DDR-SDRAM, DDR1 DIMM Memory 10 February 2010 13:54 UTC www.memoryx.net [Source type: General]
  • DDR, DDR2 and DDR3 SDRAM memory modules 10 February 2010 13:54 UTC www.valuemedia.co.uk [Source type: General]
  • DDR 400Mhz, PC3200 SDRAM memory modules 10 February 2010 13:54 UTC www.valuemedia.co.uk [Source type: General]

^ Any chip count not divisible by three or five indicates a non-parity memory module.
  • What is DDR SDRAM and Rambus RAM? Rambus,DDR SDRAM,RAM RDRAM RAMBUS Memory 10 February 2010 13:54 UTC www.rdramrambusmemory.com [Source type: FILTERED WITH BAYES]

^ Parity and ECC memory modules have a chip count divisible by three or five.
  • What is DDR SDRAM and Rambus RAM? Rambus,DDR SDRAM,RAM RDRAM RAMBUS Memory 10 February 2010 13:54 UTC www.rdramrambusmemory.com [Source type: FILTERED WITH BAYES]

.As DDR SDRAM is superseded by the newer DDR2 SDRAM, the older DDR version is sometimes referred to as DDR1 SDRAM.^ SDRAM/DDR/DDR2 controller .

^ As DDR-SDRAM is superseded by the newer DDR2 SDRAM, the older version is sometimes referred to as DDR1-SDRAM. .
  • DDR Memory, DDR-SDRAM, DDR1 DIMM Memory 10 February 2010 13:54 UTC www.memoryx.net [Source type: General]

^ DDR2 started to become competitive with the older DDR standard by the end of 2004, as modules with lower latencies became available.
  • DDR DDR2 and SDRAM Memory RAM Modules 10 February 2010 13:54 UTC www.ddrmemoryram.com [Source type: General]

Contents

Specification standards

Chips and modules

Standard name Memory clock (MHz) Cycle time[4] (ns) I/O bus clock (MHz) Data transfer rate (MHz) JEDEC standard VDDQ voltage (V) Module name Peak transfer rate (MB/s)
DDR-200 100 10 100 200 2.5±0.2 PC-1600 1600
DDR-266 133 7.5 133 266 2.5±0.2 PC-2100 2100
DDR-333 166 6 166 333 2.5±0.2 PC-2700 2700
DDR-400 200 5 200 400 2.6±0.1 PC-3200 3200
.Note: All above listed are specified by JEDEC as JESD79.[5] All RAM data rates in-between or above these listed specifications are not standardized by JEDEC—often they are simply manufacturer optimizations using higher-tolerance or overvolted chips.^ But it is used as the name for single data rate memory chips as a rule.
  • What's the difference between DDR SDRam and SDRam? - TweakTown Forums 10 February 2010 13:54 UTC forums.tweaktown.com [Source type: General]

^ The DDR SDRAM is an enhanced version of the old school SD RAM. Known as double data rate synchronous dynamic random access memory this chip has a much greater bandwidth to offer to its users.
  • 400mhz 184 Pin DDR SDRAM Desktop Memory | Desktop Memory - The Best Memory Solution for Your Desktop PC 10 February 2010 13:54 UTC desktopmemory.info [Source type: General]

^ DDR2 and DDR3 DDR2 chips increase data rates using various techniques such as on-die termination, which places the terminating transistors that eliminate excess signal noise on the chip itself.
  • ChannelWeb : Tools and information for the solution provider community. 10 February 2010 13:54 UTC www.crn.com [Source type: Reference]
  • SDRAM Definition from PC Magazine Encyclopedia 10 February 2010 13:54 UTC www.pcmag.com [Source type: General]

The package sizes in which DDR SDRAM is manufactured are also standardized by JEDEC.
.There is no architectural difference between DDR SDRAM designed for different clock frequencies, for example, PC-1600, designed to run at 100 MHz, and PC-2100, designed to run at 133 MHz.^ PC-1600 (designed to run at 100 MHz) and PC-2100 (designed to run at 133 MHz).
  • DDR, DDR2 and DDR3 SDRAM memory modules 10 February 2010 13:54 UTC www.valuemedia.co.uk [Source type: General]
  • DDR 400Mhz, PC3200 SDRAM memory modules 10 February 2010 13:54 UTC www.valuemedia.co.uk [Source type: General]

^ The difference between DDR and SDRAM DIMM modules is shown below.
  • Kingston Technology Company - New Technology - DDR vs SDRAM 10 February 2010 13:54 UTC www.kingston.com [Source type: General]

^ Can sdram be used in a PC with a ddr ram?
  • WikiAnswers - Can you have SDRAM and DDR RAM modules on the same motherboard 10 February 2010 13:54 UTC wiki.answers.com [Source type: General]

.The number simply designates the data rate at which the chip is guaranteed to perform, hence DDR SDRAM is guaranteed to run at lower and can possibly run at higher clock rates than those for which it was made.^ DDR SDRAM (double data-rate SDRAM).
  • ddr sdram | Tags | ComputerWeekly.com 10 February 2010 13:54 UTC www.computerweekly.com [Source type: General]

^ Designing for 1Gb DDR SDRAM Designing for 1Gb DDR SDRAM .
  • Micron Memory Products-DDR DRAM-Technotes 10 February 2010 13:54 UTC www.micron.com [Source type: Reference]

^ DDR SDRAM Chips Part number 6002247 .
  • Gateway Support - DDR SDRAM Chips 10 February 2010 13:54 UTC support.gateway.com [Source type: General]

[6] These practices are known as underclocking and overclocking respectively.
.DDR SDRAM modules for desktop computers, commonly called DIMMs, have 184 pins (as opposed to 168 pins on SDRAM, or 240 pins on DDR2 SDRAM), and can be differentiated from SDRAM DIMMs by the number of notches (DDR SDRAM has one, SDRAM has two).^ DDR2 and DDR3 use 240-pin DIMM modules.
  • ChannelWeb : Tools and information for the solution provider community. 10 February 2010 13:54 UTC www.crn.com [Source type: Reference]
  • SDRAM Definition from PC Magazine Encyclopedia 10 February 2010 13:54 UTC www.pcmag.com [Source type: General]

^ DDR-SDRAM is also called SDRAM II. and DDRAM .
  • eSecurity Planet: Software & Internet Security Trends, Virus Alerts 10 February 2010 13:54 UTC esecurity.webopedia.com [Source type: General]
  • DDR-SDRAM - Ultrawideband Planet 10 February 2010 13:54 UTC uwb.webopedia.com [Source type: Academic]

^ PC2 3200 400Mhz 240 Pin DDR2 Memory DIMM .
  • DDR MEMORY RAM, DDR PC2100, PC2700, PC3200, PC4200. DDR RAM Memory 10 February 2010 13:54 UTC www.ddrmemoryram.com [Source type: General]
  • Installing RAM DDR SDRAM DIMM Module - DDR Memory Upgrades 10 February 2010 13:54 UTC www.ddrmemoryupgrades.com [Source type: General]

.DDR SDRAM for notebook computers, SO-DIMMs, have 200 pins, which is the same number of pins as DDR2 SO-DIMMs.^ Pin DDR2 SDRAM (283) .
  • Newegg.com - Memory, DDR Memory, SDRAM Memory, Computer Memory, Computer RAM, DDR RAM, Memory Stick, Memory Upgrades 10 February 2010 13:54 UTC www.newegg.com [Source type: General]
  • Newegg.com - Memory, DDR Memory, SDRAM Memory, Computer Memory, Computer RAM, DDR RAM, Memory Stick, Memory Upgrades 10 February 2010 13:54 UTC e3wwwtest.newegg.com [Source type: General]

^ DDR SDRAM computer memory .
  • Computer Memory and Digital Camera Compact Flash Memory for Dell DDR HP Compaq Sony and Gateway 10 February 2010 13:54 UTC bizmemory.com [Source type: General]

^ DDR SDRAM is being supplanted by DDR2 SDRAM .
  • DDR SDRAM 10 February 2010 13:54 UTC www.topbits.com [Source type: General]

.These two specifications are notched very similarly and care must be taken during insertion if unsure of a correct match.^ These two specifications are notched very similarly and care must be taken during insertion when you are unsure of a correct match .
  • DDR SDRAM and Rambus RAM PC 1600 PC 2100 DDR RAM 10 February 2010 13:54 UTC ddrmemoryupgrades.com [Source type: General]
  • What is DDR SDRAM Memory RAM ? DDR SDRAM MEMORY - 266mhz PC2100 and 333mhz PC2700 DDR Memory 10 February 2010 13:54 UTC www.ddrsdrammemory.com [Source type: General]

.DDR SDRAM operates at a voltage of 2.5 V, compared to 3.3 V for SDRAM. This can significantly reduce power consumption.^ DDR-II SDRAM provides designers technical and economic benefits as compared to SDRAM and DDR-I. For example, DDR-II memory offers at least a 4 times speed increase over SDRAM and 2 or more times speed increase over DDR. DDR-II architecture offers reduced signal latency and lower power through the use of SSTL_18 transistor technology.
  • "DDR-II SDRAM Technology and Design Trends" 10 February 2010 13:54 UTC www.nesa.com [Source type: Academic]

^ Chips with DDR technology also save power because they run at 2.5 or 2.6 volts rather than the higher voltages used by the earlier technologies.
  • STEC | DRAM | DDR Memory | Advancement Over SDRAM Technology that Increases Memory Bandwidth & Performance 10 February 2010 13:54 UTC www.stec-inc.com [Source type: Reference]

^ DDR-SDRAM also consumes less power, which makes it well-suited to notebook computers .
  • DDR-SDRAM - Ultrawideband Planet 10 February 2010 13:54 UTC uwb.webopedia.com [Source type: Academic]

Chips and modules with DDR-400/PC-3200 standard have a nominal voltage of 2.6 V.
.Many new chipsets use these memory types in dual-channel configurations, which doubles or quadruples the effective bandwidth.^ Though it has to be supported by the motherboard and the memory must be the dual channel type.

^ Will this new memory type be able to live ...
  • Components Memory Reviews - DDR-SDRAM Has Finally Arrived - Ram Guide - Rambus on Alternate Platforms 10 February 2010 13:54 UTC www.tomshardware.com [Source type: FILTERED WITH BAYES]

^ What are these new types of memory and how do they work?

Chip characteristics

DRAM density
Size of the chip in megabits. For example, 256 Mbit, or 32 MB chip. .Nearly all motherboards only recognize 1 GB modules if they are low density 64M×8 modules.^ Not only do modules have to dissipate self-created heat, but they also are (in most cases) sandwiched next to hot-running processors, chipsets, and graphics cards, all of which are outputting tremendous amounts of heat nearby.
  • OCZ Flex XLC Water-Cooled CAS-3 DDR2-800 2GB Memory Kit - HotHardware 10 February 2010 13:54 UTC hothardware.com [Source type: General]

^ They are becoming the de-facto standard for all designers who wish to integrate large amounts of low-cost memory into their designs.
  • DDR SDRAM—Memory Solutions Center 10 February 2010 13:54 UTC www.altera.com [Source type: Academic]

^ The fact that nearly all high-end memory module and graphics card memory manufacturers use some sort of additional cooling doesn't seem to matter.
  • OCZ Flex XLC Water-Cooled CAS-3 DDR2-800 2GB Memory Kit - HotHardware 10 February 2010 13:54 UTC hothardware.com [Source type: General]

.If high density 128M×4 1 GB modules are used, they most likely will not work.^ A 256 byte serial EEPROM on board can be used to store module information such as timing, configuration, density, etc.
  • Ddr Pc2700: Memory from Kingston, Crucial Technology, Avant North America, & more @ Comp-U-Plus 10 February 2010 13:54 UTC www.compuplus.com [Source type: General]
  • Ddr Pc2700: Memory from Kingston, Crucial Technology, Avant North America, & more @ Comp-U-Plus 10 February 2010 13:54 UTC www.compuplus.com [Source type: General]

^ Marketing Information The TS128MSD64V4A is a 128M x 64bits Double Data Rate SDRAM high-density for DDR400.
  • 1GB DDR SDRAM Memory Module - 1GB (1 x 1GB) - 400MHz DDR400/PC3200 - Non-ECC - DDR SDRAM - 200-pin SoDIMM 10 February 2010 13:54 UTC www.wynit.com [Source type: General]

^ Most systems that have motherboards that use SIMM memory modules require you to use matching pairs of modules to fill a bank of slots on your motherboard.
  • What is DDR SDRAM and Rambus RAM? Rambus,DDR SDRAM,RAM RDRAM RAMBUS Memory 10 February 2010 13:54 UTC www.rdramrambusmemory.com [Source type: FILTERED WITH BAYES]

.The JEDEC standard allows 128M×4 only for slower buffered/registered modules designed specifically for some servers, but some generic manufacturers do not comply.^ JEDEC has set standards for speeds of DDR SDRAM, divided into two parts: The first specification is for memory chips and the second is for memory modules.
  • DDR Memory, DDR-SDRAM, DDR1 DIMM Memory 10 February 2010 13:54 UTC www.memoryx.net [Source type: General]
  • 1GB DDR SDRAM PC Memory - HiTechVendors.com 10 February 2010 13:54 UTC www.hitechvendors.com [Source type: General]
  • DDR-333 DDR SDRAM PC Memory - HiTechVendors.com 10 February 2010 13:54 UTC www.hitechvendors.com [Source type: General]

^ Most workstations require either standard desktop non-ECC Unbuffered or ECC Unbuffered RAM, while servers generally require ECC Registered RAM. Most motherboards that support Non-ECC or ECC Unbuffered memory will not work with ECC Registered RAM. Be sure to check your product manual for compatibility.
  • GeeK NoiZe - Used Server Memory including SDRAM and DDR ECC Registered and ECC Unbuffered RAM 10 February 2010 13:54 UTC www.geeknoize.com [Source type: Academic]

^ Fully buffered — Designed for next-generation servers, features an advanced memory buffer.
  • M470L6524BTO, 512MB SODIMM PC2700 DDR SAMSUNG ORIGINAL 10 February 2010 13:54 UTC www.memoryamerica.com [Source type: General]
  • M368L2923FLN, 1GB PC3200 DDR SAMSUNG ORIGINAL 10 February 2010 13:54 UTC www.memoryamerica.com [Source type: General]

[7]
DRAM organization
Written in the form of .64M×4, where 64M is a number of storage units (64 million), x4 (pronounced "by 4") — number of bits per chip, which equals the number of bits per storage unit.^ Supports up to eight chip-selects, up to eight banks per chip, twelve to fifteen row bits, and nine to twelve columns bits.
  • DDR IP Core - DDR2-SDRAM-CTRL DDR/DDR2 and Mobile DDR SDRAM DIMM Controller from CAST, Inc. 10 February 2010 13:54 UTC www.cast-inc.com [Source type: FILTERED WITH BAYES]

^ Specification Mfr Part Number: D512M333SB Type: DDR Capacity: 512 MB Speed: PC2700 333MHz Size & Bit: 64 x 8 Pins: 184pin ECC: No Registered: No Chips: Samsung CL 2.5 .
  • SuperBiiz.com - Memory, DDR Computer Memory, DDR SDRAM DIMM-184 Pins 10 February 2010 13:54 UTC www.ewiz.com [Source type: Reference]

^ Specification Mfr Part Number: D21PA12H Type: DDR Capacity: 512MB Speed: PC2100 DDR266 Size & Bit: 64x64/64x8 8-Chip .
  • SuperBiiz.com - Memory, DDR Computer Memory, DDR SDRAM DIMM-184 Pins 10 February 2010 13:54 UTC www.ewiz.com [Source type: Reference]

There are ×4, ×8, and ×16 DDR chips. .The ×4 chips allow the use of advanced error correction features like Chipkill, memory scrubbing and Intel SDDC, while the ×8 and ×16 chips are somewhat more expensive.^ More expensive memory which isn't being used.
  • 333MHz DDR SDRAM in next eMac? - AppleInsider 10 February 2010 13:54 UTC forums.appleinsider.com [Source type: FILTERED WITH BAYES]

^ They connect to the motherboard in a similar way as SDRAM. DDR memory supports both ECC (error correction code, typically used in servers) and non-parity (used on desktops/laptops).
  • InformIT: A+ ExamCram 2: Memory: Types and Forms > Double Data Rate SDRAM (DDR SDRAM) 10 February 2010 13:54 UTC www.informit.com [Source type: FILTERED WITH BAYES]

^ DDR2 introduces some new features which allow it to ramp up to much higher speeds (with correspondingly higher bandwidth) and higher memory densities, all the while using less power.
  • DDR MEMORY RAM, DDR PC2100, PC2700, PC3200, PC4200. DDR RAM Memory 10 February 2010 13:54 UTC www.ddrmemoryram.com [Source type: General]
  • Installing RAM DDR SDRAM DIMM Module - DDR Memory Upgrades 10 February 2010 13:54 UTC www.ddrmemoryupgrades.com [Source type: General]

Module characteristics

Capacity
Number of DRAM Devices
The number of chips is a multiple of 8 for non-ECC modules and a multiple of 9 for ECC modules. .Chips can occupy one side (single sided) or both sides (dual sided) of the module.^ The module can be single-sided (with memory chips on one side of the module only) or double-sided (with memory chips on both sides of the module)..
  • What is DDR SDRAM and Rambus RAM? Rambus,DDR SDRAM,RAM RDRAM RAMBUS Memory 10 February 2010 13:54 UTC www.rdramrambusmemory.com [Source type: FILTERED WITH BAYES]

^ If a system supports it, installing memory in matched sets of 2 or 3 modules (dual channel or triple channel modes) will deliver greatly increased memory performance over running a single memory module by itself.
  • Crucial FAQ - Answer 10 February 2010 13:54 UTC www.crucial.com [Source type: General]

^ ODT improves the eye-diagram over SSTL for either Single-Rank or Dual-Rank modules.
  • DDR3 DIMM Memory Module Manufacturers and Description, Double Data Rate Memory, DDR III 10 February 2010 13:54 UTC www.interfacebus.com [Source type: Reference]

The maximum number of chips per DDR module is 36 (9×4) for ECC and 32 (8x4) for non-ECC.
ECC vs non-ECC
Modules that have error correcting code are labeled as ECC. .Modules without error correcting code are labeled non-ECC.^ ECC stands for Error-Correcting Code .
  • What is DDR SDRAM and Rambus RAM? Rambus,DDR SDRAM,RAM RDRAM RAMBUS Memory 10 February 2010 13:54 UTC www.rdramrambusmemory.com [Source type: FILTERED WITH BAYES]

^ They connect to the motherboard in a similar way as SDRAM. DDR memory supports both ECC (error correction code, typically used in servers) and non-parity (used on desktops/laptops).
  • InformIT: A+ ExamCram 2: Memory: Types and Forms > Double Data Rate SDRAM (DDR SDRAM) 10 February 2010 13:54 UTC www.informit.com [Source type: FILTERED WITH BAYES]

^ Some other thing to keep in mind when ordering your RAM. Many desktop systems or computers use what’s called “non-parity” memory which means it does not need ECC (error correction code) or “parity” modules.
  • PC3200 DDR SDRAM Desktop Memory | Desktop Memory - The Best Memory Solution for Your Desktop PC 10 February 2010 13:54 UTC desktopmemory.info [Source type: General]

Number of DRAM Ranks
(also known as rows or .sides) Any given module can have 1, 2, or 4 ranks, but only 1 rank of a module can be active at any moment in time.^ The module can be single-sided (with memory chips on one side of the module only) or double-sided (with memory chips on both sides of the module)..
  • What is DDR SDRAM and Rambus RAM? Rambus,DDR SDRAM,RAM RDRAM RAMBUS Memory 10 February 2010 13:54 UTC www.rdramrambusmemory.com [Source type: FILTERED WITH BAYES]

.When a module has two or more ranks, the memory controller must periodically switch between them by performing close and open operations.^ This enables switching between different memory devices and modification of timing parameters to suit the application using the same netlist.
  • DDR SDRAM Controller - Pipelined 10 February 2010 13:54 UTC www.latticesemi.com [Source type: Reference]

^ JEDEC has set standards for speeds of DDR SDRAM, divided into two parts: The first specification is for memory chips and the second is for memory modules.
  • 1GB DDR SDRAM PC Memory - HiTechVendors.com 10 February 2010 13:54 UTC www.hitechvendors.com [Source type: General]

^ First - what is DDR SDRAM? Basically it’s SDRAM memory that has the ability to perform two operations per cycle, or 'Double Data Rate', instead of just one like standard SDRAM memory.
  • Real World Technologies - DDR SDRAM - A First Glance 10 February 2010 13:54 UTC www.realworldtech.com [Source type: General]

.Do not confuse rows in this context with rows used to describe internal chip architecture (that is why the term rank is to be preferred).^ Technically, the first column of the table lists the name used to describe individual RAM chips, and the second column is the name used to describe a complete DIMM. However, the two types of terminology are often used in confusing ways, and it best to keep both terms in mind when looking for a particular type.
  • ACP-EP 512MB DDR SDRAM Memory Module - 512MB - 133MHz DDR266/PC2100 - DDR SDRAM - 200-pin Laptop Memory RAM (Random Access Memory) reviews - CNET Reviews 10 February 2010 13:54 UTC reviews.cnet.com [Source type: General]

^ A is a combination of the chip select, bank select, and row addresses described in the previous section.

^ What is a generic term used to describe any card inserted onto the motherboard of a computer to add functions such as sound and video?
  • WikiAnswers - Can you have SDRAM and DDR RAM modules on the same motherboard 10 February 2010 13:54 UTC wiki.answers.com [Source type: General]

.The term sides is also confusing because it incorrectly suggests that this is tied to the physical placement of chips on the module.^ The module can be single-sided (with memory chips on one side of the module only) or double-sided (with memory chips on both sides of the module)..
  • What is DDR SDRAM and Rambus RAM? Rambus,DDR SDRAM,RAM RDRAM RAMBUS Memory 10 February 2010 13:54 UTC www.rdramrambusmemory.com [Source type: FILTERED WITH BAYES]

Timings
.CAS latency (CL), clock cycle time (tCK), row cycle time (tRC), refresh row cycle time (tRFC), row active time (tRAS).^ This can be confusing, especially since these nanosecond markings no longer measure access time, but instead measure the number of nanoseconds between clock cycles.
  • DDR FAQs - Princeton Technology - The Memory Experts! 10 February 2010 13:54 UTC www.princetonusa.com [Source type: General]

^ SDRAM: This is the most common type of memory used today and is a type of DIMM. SDRAM (like all memory) is measured by its access time, CAS latency, its rating, and other timings.
  • what is SD RAM, DDR RAM and what is the difference between... - Q&A 10 February 2010 13:54 UTC www.faqs.org [Source type: General]

^ This provides a refresh cycle every 32 AHB clock cycles.
  • ARM PrimeCell™ MultiPort Memory Controller (PL176) Technical Reference Manual 7.12. Micron MT46V8M16 DDR-SDRAM initializationexample 10 February 2010 13:54 UTC infocenter.arm.com [Source type: Reference]

Buffering
registered (or buffered) vs unbuffered
Packaging
Typically DIMM or SO-DIMM
Power consumption
Increases with clock rate.[8]
Module and chip characteristics are inherently linked.
.Total module capacity is a product of one chip's capacity by the number of chips.^ It supports non-ECC, unbuffered modules only, up to a total of 1GB. Currently has one 256MB SDRAM PC133 module in it and I want to add a new 512MB module.
  • Mixing DDR and SDR SDRAM modules on EliteGroup (ECS) K7S5A motherboard? - Motherboards, CPUs and RAM 10 February 2010 13:54 UTC www.daniweb.com [Source type: FILTERED WITH BAYES]

^ For a 168-pin DIMM module that has eight chips (no parity chip), and the part number - TMS626812DGE-12A - you would use TMS626812 to search for information on it.
  • What is DDR SDRAM and Rambus RAM? Rambus,DDR SDRAM,RAM RDRAM RAMBUS Memory 10 February 2010 13:54 UTC www.rdramrambusmemory.com [Source type: FILTERED WITH BAYES]

^ Specification Mfr Part Number: D21PA12H Type: DDR Capacity: 512MB Speed: PC2100 DDR266 Size & Bit: 64x64/64x8 8-Chip .
  • SuperBiiz.com - Memory, DDR Computer Memory, DDR SDRAM DIMM-184 Pins 10 February 2010 13:54 UTC www.ewiz.com [Source type: Reference]

.ECC modules multiply it by 8/9 because they use one bit per byte for error correction.^ ECC stands for Error-Correcting Code .
  • What is DDR SDRAM and Rambus RAM? Rambus,DDR SDRAM,RAM RDRAM RAMBUS Memory 10 February 2010 13:54 UTC www.rdramrambusmemory.com [Source type: FILTERED WITH BAYES]

^ They connect to the motherboard in a similar way as SDRAM. DDR memory supports both ECC (error correction code, typically used in servers) and non-parity (used on desktops/laptops).
  • InformIT: A+ ExamCram 2: Memory: Types and Forms > Double Data Rate SDRAM (DDR SDRAM) 10 February 2010 13:54 UTC www.informit.com [Source type: FILTERED WITH BAYES]

^ Chipkill provides error correction for up to four bits per DIMM. If too many memory errors are detected chipkill technology can take the inoperative chip offline while the server is still running to keep more errors from occurring.
  • DDR FAQs - Princeton Technology - The Memory Experts! 10 February 2010 13:54 UTC www.princetonusa.com [Source type: General]

.A module of any particular size can therefore be assembled either from 32 small chips (36 for ECC memory), or 16(18) or 8(9) bigger ones.^ JEDEC has set standards for speeds of DDR SDRAM, divided into two parts: The first specification is for memory chips and the second is for memory modules.
  • DDR-333 DDR SDRAM PC Memory - HiTechVendors.com 10 February 2010 13:54 UTC www.hitechvendors.com [Source type: General]

^ Although DDR & RAMBUS have the same pin count, they are keyed differently and therefore these disparate RAM Module Technologies are not Memory Slot compatible.
  • BBPC News | BuildOrBuy Memory... Simms, DIMMS - PC100, PC133, Intel'sRAMBUS & AMD's DDR 10 February 2010 13:54 UTC www.buildorbuy.org [Source type: FILTERED WITH BAYES]

^ Therefore, Kingston has developed an industry leading quality process to ensure that Kingston memory delivers superior quality, performance, and 100% compatibility with the computing system the module is designed for.
  • http://www.nextdaypc.com/main/products/details.aspx?PID=0002178&rsmainid=ND0021996 10 February 2010 13:54 UTC www.nextdaypc.com [Source type: General]

.DDR memory bus width per channel is 64 bits (72 for ECC memory).^ You can use this technique to work out the speed of other memory, but beware RDRAM has eight bit registers rather than the 64 bit width on SDRAM. .
  • 3DSpotlight | DDR SDRAM shoot out: Crucial PC2100 vs. OCZ PerformancePC2400 10 February 2010 13:54 UTC www.techspot.com [Source type: General]
  • 3DSpotlight | DDR SDRAM shoot out: Crucial PC2100 vs. OCZ PerformancePC2400 10 February 2010 13:54 UTC www.techspot.com [Source type: General]

^ The bandwidth is found by multiplying the effective frequency (which in the case of DDR is twice the number of clock cycles) by the width of the memory (in the case of SDRAM this is 64 bit) and dividing the result by the number of bits per byte, which is always 8.
  • 3DSpotlight | DDR SDRAM shoot out: Crucial PC2100 vs. OCZ PerformancePC2400 10 February 2010 13:54 UTC www.techspot.com [Source type: General]
  • 3DSpotlight | DDR SDRAM shoot out: Crucial PC2100 vs. OCZ PerformancePC2400 10 February 2010 13:54 UTC www.techspot.com [Source type: General]

^ Four 184-pin DDR SDRAM DIMM sockets Supports dual channel (128-bit wide) memory interface Supports up to 4GB system memory Supports PC2100 (DDR266), PC2700 (DDR333) and PC3200 (DDR400) DDR SDRAM DIMM .
  • The DFI RDX200 CF-DR Motherboard Review - Introduction - Legit Reviews 10 February 2010 13:54 UTC www.legitreviews.com [Source type: General]

.Total module bit width is a product of bits per chip by number of chips.^ The bandwidth is found by multiplying the effective frequency (which in the case of DDR is twice the number of clock cycles) by the width of the memory (in the case of SDRAM this is 64 bit) and dividing the result by the number of bits per byte, which is always 8.
  • 3DSpotlight | DDR SDRAM shoot out: Crucial PC2100 vs. OCZ PerformancePC2400 10 February 2010 13:54 UTC www.techspot.com [Source type: General]
  • 3DSpotlight | DDR SDRAM shoot out: Crucial PC2100 vs. OCZ PerformancePC2400 10 February 2010 13:54 UTC www.techspot.com [Source type: General]

^ For a 168-pin DIMM module that has eight chips (no parity chip), and the part number - TMS626812DGE-12A - you would use TMS626812 to search for information on it.
  • What is DDR SDRAM and Rambus RAM? Rambus,DDR SDRAM,RAM RDRAM RAMBUS Memory 10 February 2010 13:54 UTC www.rdramrambusmemory.com [Source type: FILTERED WITH BAYES]

^ Volume production of DDR2 chips and modules started in the latter part of 2003, with supporting chipsets and motherboards arriving in mid-2004.
  • SDRAM 10 February 2010 13:54 UTC e-articles.info [Source type: FILTERED WITH BAYES]

.It also equals number of ranks (rows) multiplied by DDR memory bus width.^ The most commonly seen memory specifications are those for SPEED! Numbers similar to PC3200 and DDR-333.
  • Premium 512MB PC2100 DDR 266MHz Memory at TigerDirect.com 10 February 2010 13:54 UTC www.tigerdirect.com [Source type: General]

^ Kingston Memory 1GB PC2700 DDR SDRAM DIMMx8 Dual Rank 184-pin 333MHz CL2.5 ECC Registered .
  • DDR Registered DIMM ,high quality DDR Registered DIMM for computer. 10 February 2010 13:54 UTC www.computersunlimited.com [Source type: General]

^ The memory latency does not depend on the frequency of the I/O buffers or on the width of the bus the data are coming in from the memory cells.
  • DDR2 vs. DDR: Revenge Gained (page 2) - X-bit labs 10 February 2010 13:54 UTC www.xbitlabs.com [Source type: FILTERED WITH BAYES]

.Consequently a module with greater amount of chips or using ×8 chips instead of ×4 will have more ranks.^ These modules are mostly manufacturer optimizations of highest-yielding chips, drawing significantly more power than slower-clocked modules, and usually do not offer much, if any, greater real-world performance.
  • what is SD RAM, DDR RAM and what is the difference between... - Q&A 10 February 2010 13:54 UTC www.faqs.org [Source type: General]

^ For a 168-pin DIMM module that has eight chips (no parity chip), and the part number - TMS626812DGE-12A - you would use TMS626812 to search for information on it.
  • What is DDR SDRAM and Rambus RAM? Rambus,DDR SDRAM,RAM RDRAM RAMBUS Memory 10 February 2010 13:54 UTC www.rdramrambusmemory.com [Source type: FILTERED WITH BAYES]

^ However, currently manufactured PC133 memory uses different sizes of memory chips from those used by PC100 modules.
  • SDRAM 10 February 2010 13:54 UTC e-articles.info [Source type: FILTERED WITH BAYES]

Example: Variations of 1 GB PC2100 Registered DDR SDRAM module with ECC
Module size (GB) Number of chips Chip size (Mbit) Chip organization Number of rows (ranks)
1 36 256 64M×4 2
1 18 512 64M×8 2
1 18 512 128M×4 1
.This example compares different real-world server memory modules with a common size of 1 GB. One should definitely be careful buying 1 GB memory modules, because all these variations can be sold under one price position without stating whether they are ×4 or ×8, single or dual ranked.^ Tags: ram , memory , channel , dual , modules , ddr Definition of DDR RAM .
  • Tag: Ddr - Explore content tagged Ddr on eHow.com 10 February 2010 13:54 UTC www.ehow.com [Source type: General]

^ DIMM = Dual inline memory module .
  • SDRAM 10 February 2010 13:54 UTC e-articles.info [Source type: FILTERED WITH BAYES]

^ This is nearly a necessity for the performance-minded memory buyer, because individual memory modules rated to the same timings may not work together under those specifications on a given motherboard.
  • Corsair TWINX1024RE-3200LL DDR SDRAM Review - Bjorn3D.com 10 February 2010 13:54 UTC www.bjorn3d.com [Source type: General]

.There is a common belief that number of module ranks or rows equals number of sides.^ Use Single Side Memory Modules and all Modules must be of equal values.
  • BBPC News | BuildOrBuy Memory... Simms, DIMMS - PC100, PC133, Intel'sRAMBUS & AMD's DDR 10 February 2010 13:54 UTC www.buildorbuy.org [Source type: FILTERED WITH BAYES]

As above data shows, this is not true. .One can find 2-side/1-rank or 2-side/4-rank modules.^ The module can be single-sided (with memory chips on one side of the module only) or double-sided (with memory chips on both sides of the module)..
  • What is DDR SDRAM and Rambus RAM? Rambus,DDR SDRAM,RAM RDRAM RAMBUS Memory 10 February 2010 13:54 UTC www.rdramrambusmemory.com [Source type: FILTERED WITH BAYES]

.One can even think of a 1-side/2-rank memory module having 16(18) chips on single side ×8 each, but it's unlikely such a module was ever produced.^ The module can be single-sided (with memory chips on one side of the module only) or double-sided (with memory chips on both sides of the module)..
  • What is DDR SDRAM and Rambus RAM? Rambus,DDR SDRAM,RAM RDRAM RAMBUS Memory 10 February 2010 13:54 UTC www.rdramrambusmemory.com [Source type: FILTERED WITH BAYES]

^ JEDEC has set standards for speeds of DDR SDRAM, divided into two parts: The first specification is for memory chips and the second is for memory modules.
  • 1GB DDR SDRAM PC Memory - HiTechVendors.com 10 February 2010 13:54 UTC www.hitechvendors.com [Source type: General]

^ Motherboards : GA-8SG667 DDR400 (PC3200) recommended memory modules list (9/16/2002).
  • BBPC News | BuildOrBuy Memory... Simms, DIMMS - PC100, PC133, Intel'sRAMBUS & AMD's DDR 10 February 2010 13:54 UTC www.buildorbuy.org [Source type: FILTERED WITH BAYES]

History

Double data rate (DDR) SDRAM specification

From JEDEC Board Ballot JCB-99-70, and modified by numerous other Board Ballots, formulated under the cognizance of Committee JC-42.3 on DRAM Parametrics.
Standard No. 79 Revision Log:
  • Release 1, June 2000
  • Release 2, May 2002
  • Release C, March 2003 – JEDEC Standard No. 79C.[9]
."This comprehensive standard defines all required aspects of 64Mb through 1Gb DDR SDRAMs with X4/X8/X16 data interfaces, including features, functionality, ac and dc parametrics, packages and pin assignments.^ Features » Interfaces directly to all industry standard DDR and DDR-II SDRAM DIMMs and chips.
  • Alma Technologies 10 February 2010 13:54 UTC www.alma-tech.com [Source type: General]

^ DDR SDRAM (double data-rate SDRAM).
  • ddr sdram | Tags | ComputerWeekly.com 10 February 2010 13:54 UTC www.computerweekly.com [Source type: General]

^ Pin DDR SDRAM (92) .
  • Newegg.com - Memory, DDR Memory, SDRAM Memory, Computer Memory, Computer RAM, DDR RAM, Memory Stick, Memory Upgrades 10 February 2010 13:54 UTC www.newegg.com [Source type: General]
  • Newegg.com - Memory, DDR Memory, SDRAM Memory, Computer Memory, Computer RAM, DDR RAM, Memory Stick, Memory Upgrades 10 February 2010 13:54 UTC e3wwwtest.newegg.com [Source type: General]

.This scope will subsequently be expanded to formally apply to x32 devices, and higher density devices as well."^ The latter rate applies to DDR, DDR2, DDR3, GDDR, GDDR2 and GDDR3 SDRAM devices, as well as DDR SGRAM devices.
  • Hynix Settles to Pay Rambus Royalties - Tom's Hardware 10 February 2010 13:54 UTC www.tomshardware.com [Source type: FILTERED WITH BAYES]

High density vs low density

.High density memory here means non-ECC 184 pin SDRAM memory.^ DDR SDRAM DIMM - 184 Pins .
  • SuperBiiz.com - Memory, DDR Computer Memory, DDR SDRAM DIMM-184 Pins 10 February 2010 13:54 UTC www.ewiz.com [Source type: Reference]

^ DDR SDRAM memory has 184 pins, where as SDRAM has 168 pins.
  • DDR MEMORY - DDR2 PC3200 and 333MHz PC2700 DDR Memory RAM 10 February 2010 13:54 UTC www.ddrsdrammemory.com [Source type: General]

^ They connect to the motherboard in a similar way as SDRAM. DDR memory supports both ECC (error correction code, typically used in servers) and non-parity (used on desktops/laptops).
  • InformIT: A+ ExamCram 2: Memory: Types and Forms > Double Data Rate SDRAM (DDR SDRAM) 10 February 2010 13:54 UTC www.informit.com [Source type: FILTERED WITH BAYES]

Organization

.PC3200 is DDR SDRAM designed to operate at 200 MHz using DDR-400 chips with a bandwidth of 3,200 MB/s.^ PC3200 512MB DDR SDRAM 512 MB 400 mhz 184 pin PC MEMORY .
  • eBay - Memory PC3200 PC2700 DDR DDR SDRAM, Similar items search 10 February 2010 13:54 UTC shop.ebay.com [Source type: FILTERED WITH BAYES]
  • eBay Store - A-Living: DDR2 PC 1-2GB, DDR PC 1-2GB, DDR PC 512MB 10 February 2010 13:54 UTC stores.ebay.com [Source type: FILTERED WITH BAYES]

^ Can sdram be used in a PC with a ddr ram?
  • WikiAnswers - Can you have SDRAM and DDR RAM modules on the same motherboard 10 February 2010 13:54 UTC wiki.answers.com [Source type: General]

^ MHz DDR SDRAM in next eMac?
  • 333MHz DDR SDRAM in next eMac? - AppleInsider 10 February 2010 13:54 UTC forums.appleinsider.com [Source type: FILTERED WITH BAYES]

.As the memory is double pumped, this means that the effective clock rate of PC3200 memory is 400 MHz.^ DDR SDRAM: Double data rate synchronous dynamic RAM is just like SDRAM except that is has higher bandwidth, meaning greater speed.
  • WikiAnswers - Can you have SDRAM and DDR RAM modules on the same motherboard 10 February 2010 13:54 UTC wiki.answers.com [Source type: General]

^ PC3200 is a type of computer random access memory or RAM. The numerical designation indicates the maximum clock speed that the RAM can achieve, which is 400 MHz in the case of PC3200 RAM. .
  • Tag: Ddr - Explore content tagged Ddr on eHow.com 10 February 2010 13:54 UTC www.ehow.com [Source type: General]

^ In DDR memories, data is clocked both on the rising edge and on the falling edge of the clock, effectively doubling the raw bandwidth over SDR. Today, DDR memories are widely used in computers, servers, storage, and networking and communication equipment.
  • DDR SDRAM—Memory Solutions Center 10 February 2010 13:54 UTC www.altera.com [Source type: Academic]

.1 GB PC3200 non-ECC modules are usually made with sixteen 512 Mbit chips, 8 down each side (512 Mbits × 16 chips) / (8 bits (per byte)) = 1,024 MB. The individual chips making up a 1 GB memory module are usually organized with 64 Mbits and a data width of 8 bits for each chip, commonly expressed as 64M×8. Memory manufactured in this way is low density RAM and will usually be compatible with any motherboard specifying PC3200 DDR-400 memory.^ DDR PC3200 400Mhz ECC .
  • DDR MEMORY - DDR2 PC3200 and 333MHz PC2700 DDR Memory RAM 10 February 2010 13:54 UTC www.ddrsdrammemory.com [Source type: General]
  • DDR MEMORY RAM, DDR PC2100, PC2700, PC3200, PC4200. DDR RAM Memory 10 February 2010 13:54 UTC www.ddrmemoryram.com [Source type: General]
  • DDR DDR2 and SDRAM Memory RAM Modules 10 February 2010 13:54 UTC www.ddrmemoryram.com [Source type: General]

^ DDR Memory: Peak bandwidth of 6.4 GB per second.
  • BBPC News | BuildOrBuy Memory... Simms, DIMMS - PC100, PC133, Intel'sRAMBUS & AMD's DDR 10 February 2010 13:54 UTC www.buildorbuy.org [Source type: FILTERED WITH BAYES]

^ GB PC3200 (DDR 400Mhz) DIMM .
  • Specify product - HP Business Support Center 10 February 2010 13:54 UTC h20000.www2.hp.com [Source type: General]

High density RAM

.In the context of the 1 GB non-ECC PC3200 SDRAM module, there is very little visually to differentiate low density from high density RAM. High density DDR RAM modules will, like their low density counterparts, usually be double-sided with eight 512 Mbit chips per side.^ GB DDR PC3200 400MHz ECC REGISTERED 184 PIN SERVER RAM .
  • eBay - Memory module ECC Registered Error Checking and Correction DDR SDRAM PC3200, Similar items search 10 February 2010 13:54 UTC shop.ebay.com [Source type: FILTERED WITH BAYES]

^ Can sdram be used in a PC with a ddr ram?
  • WikiAnswers - Can you have SDRAM and DDR RAM modules on the same motherboard 10 February 2010 13:54 UTC wiki.answers.com [Source type: General]

^ DDR PC3200 400Mhz ECC .
  • DDR MEMORY RAM, DDR PC2100, PC2700, PC3200, PC4200. DDR RAM Memory 10 February 2010 13:54 UTC www.ddrmemoryram.com [Source type: General]
  • Installing RAM DDR SDRAM DIMM Module - DDR Memory Upgrades 10 February 2010 13:54 UTC www.ddrmemoryupgrades.com [Source type: General]

.The difference is that each chip instead of being organized in a 64M×8 configuration is organized with 128 Mbits and a data width of 4 bits, or 128M×4. To further confuse the issue, some RAM is labeled as 128M×8, and is also called high density.^ Designed by Rambus, RDRAM uses a Rambus in-line memory module (RIMM), which is similar in size and pin configuration to a standard DIMM. What makes RDRAM so different is its use of a special high-speed data bus called the Rambus channel.
  • WikiAnswers - Can you have SDRAM and DDR RAM modules on the same motherboard 10 February 2010 13:54 UTC wiki.answers.com [Source type: General]

^ Data strobes are organized per byte of the 32 bit wide interface.

^ RDRAM also developed a different type of chip packaging called Fine Pitch Ball Grid Array (FPBGA).
  • InformIT: A+ ExamCram 2: Memory: Types and Forms > Double Data Rate SDRAM (DDR SDRAM) 10 February 2010 13:54 UTC www.informit.com [Source type: FILTERED WITH BAYES]

.Most high density PC3200 modules are assembled using Samsung chips.^ A 256 byte serial EEPROM on board can be used to store module information such as timing, configuration, density, etc.
  • Ddr Pc2700: Memory from Kingston, Crucial Technology, Avant North America, & more @ Comp-U-Plus 10 February 2010 13:54 UTC www.compuplus.com [Source type: General]
  • Ddr Pc2700: Memory from Kingston, Crucial Technology, Avant North America, & more @ Comp-U-Plus 10 February 2010 13:54 UTC www.compuplus.com [Source type: General]

^ For a 168-pin DIMM module that has eight chips (no parity chip), and the part number - TMS626812DGE-12A - you would use TMS626812 to search for information on it.
  • What is DDR SDRAM and Rambus RAM? Rambus,DDR SDRAM,RAM RDRAM RAMBUS Memory 10 February 2010 13:54 UTC www.rdramrambusmemory.com [Source type: FILTERED WITH BAYES]

^ The fact that nearly all high-end memory module and graphics card memory manufacturers use some sort of additional cooling doesn't seem to matter.
  • OCZ Flex XLC Water-Cooled CAS-3 DDR2-800 2GB Memory Kit - HotHardware 10 February 2010 13:54 UTC hothardware.com [Source type: General]

These chips come in both the familiar 22 × 10 mm (approx.) TSOP2 and smaller squarer 12 × 9 mm (approx.) FBGA package sizes. .High density Samsung chips can be identified by the numbers on each chip.^ It is possible to identify the chips by part number.
  • What is DDR SDRAM and Rambus RAM? Rambus,DDR SDRAM,RAM RDRAM RAMBUS Memory 10 February 2010 13:54 UTC www.rdramrambusmemory.com [Source type: FILTERED WITH BAYES]

^ However, the stick I bought recently (from a reputable store) had the same part number but had cheaper generic Samsung chips.
  • 1GB PC3200 DDR DIMM Memory - PC World Pricing 10 February 2010 13:54 UTC www.pcworld.com [Source type: General]

^ You have to identify the size of each the chips on a module, and then multiply the size by the number of chips on the module to determine its memory capacity.
  • What is DDR SDRAM and Rambus RAM? Rambus,DDR SDRAM,RAM RDRAM RAMBUS Memory 10 February 2010 13:54 UTC www.rdramrambusmemory.com [Source type: FILTERED WITH BAYES]

If the sixth and seventh characters are 04 (for example K4H510438D-UCCC) then the chips are ×4 and high density. If the sixth and seventh characters are 08 then the chips are ×8 and low density.
.High density RAM devices were designed to be used in registered memory modules for servers.^ Registered RAM is used mostly in servers.
  • PC3200 DDR SDRAM Desktop Memory | Desktop Memory - The Best Memory Solution for Your Desktop PC 10 February 2010 13:54 UTC desktopmemory.info [Source type: General]

^ Most workstations require either standard desktop non-ECC Unbuffered or ECC Unbuffered RAM, while servers generally require ECC Registered RAM. Most motherboards that support Non-ECC or ECC Unbuffered memory will not work with ECC Registered RAM. Be sure to check your product manual for compatibility.
  • GeeK NoiZe - Used Server Memory including SDRAM and DDR ECC Registered and ECC Unbuffered RAM 10 February 2010 13:54 UTC www.geeknoize.com [Source type: Academic]

^ Although DDR & RAMBUS have the same pin count, they are keyed differently and therefore these disparate RAM Module Technologies are not Memory Slot compatible.
  • BBPC News | BuildOrBuy Memory... Simms, DIMMS - PC100, PC133, Intel'sRAMBUS & AMD's DDR 10 February 2010 13:54 UTC www.buildorbuy.org [Source type: FILTERED WITH BAYES]

.As a result, performance or response times may suffer when used on a desktop or workstation.^ You could spend a long time transferring files from the devices to a desktop computer by using, say, USB cables.
  • What is DDR SDRAM and Rambus RAM? Rambus,DDR SDRAM,RAM RDRAM RAMBUS Memory 10 February 2010 13:54 UTC www.rdramrambusmemory.com [Source type: FILTERED WITH BAYES]

^ They performed excellent the last time they were used.
  • Crucial Ballistix Tracer 1GB (2 x 512MB) 184-Pin DDR SDRAM DDR 500 (PC 4000) - PC Perspective Forums 10 February 2010 13:54 UTC forums.pcper.com [Source type: FILTERED WITH BAYES]

^ This new memory technology enables a new generation of higher performance computer systems, including desktops, workstations, servers, and notebooks.
  • Premium 512MB PC2100 DDR 266MHz Memory at TigerDirect.com 10 February 2010 13:54 UTC www.tigerdirect.com [Source type: General]

.JEDEC standards do not apply to high-density DDR RAM in desktop implementations.^ PC2700 DDR is a type of computer memory (RAM) that is used in both desktop and laptop computers.
  • Tag: Ddr - Explore content tagged Ddr on eHow.com 10 February 2010 13:54 UTC www.ehow.com [Source type: General]

^ Hynix says its 512Mb ECC mobile DDR is manufactured on the company’s 80-nm process technology and is offered in JEDEC standard pin-out and packages.
  • Hynix touts 'industry's fastest' mobile DDR SDRAM - 3/15/2007 - Electronic News 10 February 2010 13:54 UTC www.edn.com [Source type: News]

^ Tags: ram , memory , cpu , sdram , ddr , ddr3 What are the Types of Desktop Memory?
  • Tag: Ddr - Explore content tagged Ddr on eHow.com 10 February 2010 13:54 UTC www.ehow.com [Source type: General]

.JEDEC's technical documentation, however, supports 128M×4 semiconductors as such that contradicts 128×4 being classified as high density.^ The complete solution includes technical documentation, software and tool support, intellectual property (IP) cores, demonstration boards, and simulation models.
  • DDR SDRAM—Memory Solutions Center 10 February 2010 13:54 UTC www.altera.com [Source type: Academic]

.As such, high density is a relative term, which can be used to describe memory which is not supported by a particular motherboard's memory controller.^ It suggests me that motherboard supports faster memory...
  • K7D Memory installation problem.... 10 February 2010 13:54 UTC forum-en.msi.com [Source type: General]

^ A 256 byte serial EEPROM on board can be used to store module information such as timing, configuration, density, etc.
  • Ddr Pc2700: Memory from Kingston, Crucial Technology, Avant North America, & more @ Comp-U-Plus 10 February 2010 13:54 UTC www.compuplus.com [Source type: General]
  • Ddr Pc2700: Memory from Kingston, Crucial Technology, Avant North America, & more @ Comp-U-Plus 10 February 2010 13:54 UTC www.compuplus.com [Source type: General]

^ The memory chip is designed for low-power applications such as consumer and industrial electronics and networking and telecommunications equipment that require high bandwidth and large memory density, the company said.
  • Hyundai Electronics Samples 3G DDR SDRAM Memory Device | Electronic News | Find Articles at BNET 10 February 2010 13:54 UTC findarticles.com [Source type: News]

Alternatives

Comparison of DDR, DDR2 and DDR3 for Desktop PCs
DDR SDRAM Standard Frequency (MHz) Voltage[10]
DDR 100–200 2.5/2.6
DDR2 200–533 1.8
DDR3 400–800 1.5
.DDR (DDR1) has been superseded by DDR2 SDRAM, which has some modifications to allow higher clock frequency, but operates on the same principle as DDR. Competing with DDR2 are Rambus XDR DRAM.^ DDR2 introduces some new features which allow it to ramp up to much higher speeds (with correspondingly higher bandwidth) and higher memory densities, all the while using less power.
  • DDR MEMORY - DDR2 PC3200 and 333MHz PC2700 DDR Memory RAM 10 February 2010 13:54 UTC www.ddrsdrammemory.com [Source type: General]
  • DDR MEMORY RAM, DDR PC2100, PC2700, PC3200, PC4200. DDR RAM Memory 10 February 2010 13:54 UTC www.ddrmemoryram.com [Source type: General]
  • DDR Memory Upgrades- Upgrade Memory DDR DDR2 DDR3 10 February 2010 13:54 UTC www.ddrmemoryupgrades.com [Source type: General]
  • What is DDR SDRAM Memory RAM ? DDR SDRAM MEMORY - 266mhz PC2100 and 333mhz PC2700 DDR Memory 10 February 2010 13:54 UTC www.ddrsdrammemory.com [Source type: General]

^ DDR SDRAM for desktop computers DIMMs have 184 pins (as opposed to 168 pins on SDRAM, or 240 pins on DDR2 SDRAM), and can be differentiated from SDRAM DIMMs by the number of notches (DDR SDRAM has one, SDRAM has two).
  • DDR MEMORY - DDR2 PC3200 and 333MHz PC2700 DDR Memory RAM 10 February 2010 13:54 UTC www.ddrsdrammemory.com [Source type: General]
  • DDR MEMORY RAM, DDR PC2100, PC2700, PC3200, PC4200. DDR RAM Memory 10 February 2010 13:54 UTC www.ddrmemoryram.com [Source type: General]
  • DDR Memory Upgrades- Upgrade Memory DDR DDR2 DDR3 10 February 2010 13:54 UTC www.ddrmemoryupgrades.com [Source type: General]
  • What is DDR SDRAM Memory RAM ? DDR SDRAM MEMORY - 266mhz PC2100 and 333mhz PC2700 DDR Memory 10 February 2010 13:54 UTC www.ddrsdrammemory.com [Source type: General]

^ Double data rate revision 2 memory, or DDR2, is a class of synchronous dynamic random access memory, or SDRAM. DDR2 memory supersedes the DDR memory specification set forth by the Joint Electronic...
  • Tag: Ddr - Explore content tagged Ddr on eHow.com 10 February 2010 13:54 UTC www.ehow.com [Source type: General]

.DDR2 has become the standard, as XDR is lacking support.^ DDR2 started to become competitive with the older DDR standard by the end of 2004, as modules with lower latencies became available.
  • what is SD RAM, DDR RAM and what is the difference between... - Q&A 10 February 2010 13:54 UTC www.faqs.org [Source type: General]

.DDR3 SDRAM is a new standard that offers even higher performance and new features.^ Equipped with a memory capacity of 1024MB, this DDR SDRAM offers high performance at an incredible price.
  • Kingston Technology 1 Gb Ddr Sdram : Info, Customer Reviews & Bargain Prices : Shopzilla 10 February 2010 13:54 UTC www.shopzilla.com [Source type: General]

^ The K7T Turbo2 is a budget-oriented, stable, and effective motherboard that offers continued support for SDRAM as well as the AthlonXP. The Epox 8KHA+, on the other hand, is a more expensive board with a greater feature set and higher performance.
  • VHJ:Time To Upgrade: DDR SDRAM, Athlon XP Are Worth It 10 February 2010 13:54 UTC www.vanshardware.com [Source type: General]

^ This new memory technology enables a new generation of higher performance computer systems, including desktops, workstations, servers, and notebooks.
  • Premium 512MB PC2100 DDR 266MHz Memory at TigerDirect.com 10 February 2010 13:54 UTC www.tigerdirect.com [Source type: General]

.DDR's prefetch buffer depth is 2 bits, while DDR2 uses 4 bits.^ Sometimes, certain systems use Rambus Dynamic RAM (RDRAM) or DDR2 RAM that are a bit different and are not within the scope of this article.

^ For example, the Intel 915G, 915GV, 915GL, and 915PL chipsets use dual-channel DDR memory (some also support dual-channel DDR2 memory).
  • SDRAM 10 February 2010 13:54 UTC e-articles.info [Source type: FILTERED WITH BAYES]

^ DDR2 memory uses a new form factor, a 240 pin DIMM (Dual Inline Memory Module) which is *not* compatible with current DDR memory slots.
  • DDR MEMORY - DDR2 PC3200 and 333MHz PC2700 DDR Memory RAM 10 February 2010 13:54 UTC www.ddrsdrammemory.com [Source type: General]
  • What is DDR SDRAM Memory RAM ? DDR SDRAM MEMORY - 266mhz PC2100 and 333mhz PC2700 DDR Memory 10 February 2010 13:54 UTC www.ddrsdrammemory.com [Source type: General]

.Although the effective clock rates of DDR2 are higher than for DDR, the overall performance was no greater in the early implementations, primarily due to the high latencies of the first DDR2 modules.^ DDR2 started to become competitive with the older DDR standard by the end of 2004, as modules with lower latencies became available.
  • what is SD RAM, DDR RAM and what is the difference between... - Q&A 10 February 2010 13:54 UTC www.faqs.org [Source type: General]
  • DDR DDR2 and SDRAM Memory RAM Modules 10 February 2010 13:54 UTC www.ddrmemoryram.com [Source type: General]

^ DDR memory, or Double Data Rate memory, is a new high performance type of memory that runs at twice the speed of normal SDRAM. This DDR SDRAM is ideally suited to the latest high performance processors to increase overall system speed.
  • What is DDR SDRAM Memory RAM ? DDR SDRAM MEMORY - 266mhz PC2100 and 333mhz PC2700 DDR Memory 10 February 2010 13:54 UTC www.ddrsdrammemory.com [Source type: General]

^ SD RAM stands for synchronous data ram and DDR stands for Dual Data RAM.DDR has got a higher frequency and therefore it will transfer data at a higher rate.
  • what is SD RAM, DDR RAM and what is the difference between... - Q&A 10 February 2010 13:54 UTC www.faqs.org [Source type: General]

.DDR2 started to be effective by the end of 2004, as modules with lower latencies became available.^ DDR2 started to become competitive with the older DDR standard by the end of 2004, as modules with lower latencies became available.
  • what is SD RAM, DDR RAM and what is the difference between... - Q&A 10 February 2010 13:54 UTC www.faqs.org [Source type: General]

^ Volume production of DDR2 chips and modules started in the latter part of 2003, with supporting chipsets and motherboards arriving in mid-2004.
  • SDRAM 10 February 2010 13:54 UTC e-articles.info [Source type: FILTERED WITH BAYES]

^ DDR2 chip and module production actually began in mid-2003 (mainly samples and prototypes), and the first chipsets, motherboards, and systems supporting DDR2 appeared in mid-2004.
  • SDRAM 10 February 2010 13:54 UTC e-articles.info [Source type: FILTERED WITH BAYES]

[11]
.Memory manufacturers have stated that it is impractical to mass-produce DDR1 memory with effective clock rates in excess of 400 MHz.^ PC3200 is a type of computer random access memory or RAM. The numerical designation indicates the maximum clock speed that the RAM can achieve, which is 400 MHz in the case of PC3200 RAM. .
  • Tag: Ddr - Explore content tagged Ddr on eHow.com 10 February 2010 13:54 UTC www.ehow.com [Source type: General]

^ PC3200 512MB DDR SDRAM 512 MB 400 mhz 184 pin PC MEMORY .
  • eBay Store - A-Living: DDR2 PC 1-2GB, DDR PC 1-2GB, DDR PC 512MB 10 February 2010 13:54 UTC stores.ebay.com [Source type: FILTERED WITH BAYES]

^ In case the system bus speed rate is at 100 MHz and the memory is at 66 MHz, thus the memory is not working as fast as it may be and it is recommended to purchase a PC100 memory.

.DDR2 picks up where DDR1 leaves off, and is available at clock rates of 400 MHz and higher.^ PC3200 is a type of computer random access memory or RAM. The numerical designation indicates the maximum clock speed that the RAM can achieve, which is 400 MHz in the case of PC3200 RAM. .
  • Tag: Ddr - Explore content tagged Ddr on eHow.com 10 February 2010 13:54 UTC www.ehow.com [Source type: General]

^ HP (Brzl) 256-MB PC2-3200 (DDR2 400 MHz) DIMM .
  • Specify product - HP Business Support Center 10 February 2010 13:54 UTC h20000.www2.hp.com [Source type: General]

^ HP 256-MB PC2-3200 (DDR2 400 MHz) DIMM .
  • Specify product - HP Business Support Center 10 February 2010 13:54 UTC h20000.www2.hp.com [Source type: General]

.RDRAM is a particularly expensive alternative to DDR SDRAM, and most manufacturers have dropped its support from their chipsets.^ As such, DDR SDRAM is supported by all the major processor, chipset, and memory manufacturers.
  • SDRAM 10 February 2010 13:54 UTC e-articles.info [Source type: FILTERED WITH BAYES]

^ The first Pentium 4 processors run on Socket 423 motherboards, most of which support only Rambus RAM. But the latest incarnation of P4s run on Socket 478 motherboards, some of which support DDR RAM .
  • What is DDR SDRAM and Rambus RAM? Rambus,DDR SDRAM,RAM RDRAM RAMBUS Memory 10 February 2010 13:54 UTC www.rdramrambusmemory.com [Source type: FILTERED WITH BAYES]

^ For example, the Intel 915G, 915GV, 915GL, and 915PL chipsets use dual-channel DDR memory (some also support dual-channel DDR2 memory).
  • SDRAM 10 February 2010 13:54 UTC e-articles.info [Source type: FILTERED WITH BAYES]

.DDR1 memory's prices have substantially increased since Q2 2008 while DDR2 prices are reaching an all-time low.^ Application for both DDR and SDRAM memory modules Help increase life & performance All ULTRA Memory Coolers ship in anti-static packaging.
  • Ultra Memory Aluminum Cooler (DDR or SDRAM) Purple at TigerDirect.com 10 February 2010 13:54 UTC www.tigerdirect.com [Source type: General]

^ If you find that you need more memory, we suggest expanding your system memory, since this is the most effective performance increase, and the one that is easiest to perform.
  • Premium 512MB PC2100 DDR 266MHz Memory at TigerDirect.com 10 February 2010 13:54 UTC www.tigerdirect.com [Source type: General]

^ RAMBUS did do some shady things, but let us not forget that all the major memory makers plead guilty to price fixing and collusion.
  • Slashdot | Samsung Settles With Rambus In Patent Dispute 10 February 2010 13:54 UTC slashdot.org [Source type: General]

.In January 2009, 1 GB DDR1 is 2–3 times more expensive than 1 GB DDR2. High density DDR RAM will suit about 10% of PC motherboards on the market while low density will suit almost all motherboards on the PC Desktop market.^ Tags: ram , memory , dual , modules , ddr , ddr2 What Is PC Memory?
  • Tag: Ddr - Explore content tagged Ddr on eHow.com 10 February 2010 13:54 UTC www.ehow.com [Source type: General]

^ DDR SDRAM for desktop computers DIMMs have 184 pins (as opposed to 168 pins on SDRAM, or 240 pins on DDR2 SDRAM), and can be differentiated from SDRAM DIMMs by the number of notches (DDR SDRAM has one, SDRAM has two).
  • DDR MEMORY - DDR2 PC3200 and 333MHz PC2700 DDR Memory RAM 10 February 2010 13:54 UTC www.ddrsdrammemory.com [Source type: General]
  • What is DDR SDRAM Memory RAM ? DDR SDRAM MEMORY - 266mhz PC2100 and 333mhz PC2700 DDR Memory 10 February 2010 13:54 UTC www.ddrsdrammemory.com [Source type: General]

^ We also take a peek at a few tests showing the significant advancement the Athlon XP is, and how this chip is better suited for DDR SDRAM than its predecessor.
  • VHJ:Time To Upgrade: DDR SDRAM, Athlon XP Are Worth It 10 February 2010 13:54 UTC www.vanshardware.com [Source type: General]

MDDR

.MDDR is an acronym that some enterprises use for Mobile DDR SDRAM, a type of memory used in some portable electronic devices, like mobile phones, handhelds, and digital audio players.^ Most types of memory chips used in computers including DDR,...
  • Tag: Ddr - Explore content tagged Ddr on eHow.com 10 February 2010 13:54 UTC www.ehow.com [Source type: General]

^ DDR SDRAM Memory - Shopper.com .

^ DDR SDRAM or double-data-rate synchronous dynamic random access memory is a type of memory used in computers and consumer electronics.
  • Winbond - DDR SDRAM 10 February 2010 13:54 UTC www.winbond.com [Source type: Reference]

.While standard DDR SDRAM operates at a voltage of 2.5 V, MDDR operates at voltage of 1.8 V, which allows a reduced power consumption.^ It uses lower voltage than conventional DDR (1.8V versus 2.5V), so power consumption and heat generation are reduced.
  • SDRAM 10 February 2010 13:54 UTC e-articles.info [Source type: FILTERED WITH BAYES]

^ These features allow the motherboard to operate at much higher speeds with better power management in much safer thermal environments than the traditional motherboards.
  • Ddr ii sdram Motherboards at bizrate - Price Comparison and Consumer Reviews 10 February 2010 13:54 UTC www.bizrate.com [Source type: General]

^ The tolerance for DDR operating voltage is 2.5 +/-0.1V to begin with and Crucial even recommends 2.6V for your module(s).
  • MS-6704 i845PE Socket 478 v 2.x Max 2 or Max 3? 10 February 2010 13:54 UTC forum-en.msi.com [Source type: General]

References

See also

External links


Citable sentences

Up to date as of December 27, 2010

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