The Full Wiki

Phenom II: Wikis


Note: Many of our articles have direct quotes from sources you can cite, within the Wikipedia article! This article doesn't yet, but we're working on it! See more info or our list of citable articles.


From Wikipedia, the free encyclopedia

AMD Phenom II
Produced From 2008 to Present
Marketed by AMD
Designed by AMD
Common manufacturer(s) GlobalFoundries
Max. CPU clock rate 2.5 GHz to 3.4 GHz
HyperTransport speeds 1.8 GHz to 2 GHz
Min. feature size 45 nm
Instruction set x86, x86-64, MMX, SSE, SSE2, SSE3, SSE4a
Microarchitecture AMD K10
Cores 2 or 3 or 4
Socket(s) Socket AM2+
Socket AM3
Core name(s) Deneb



Phenom II is a family of AMD's multi-core 45 nm processors using the AMD K10 microarchitecture, succeeding the original Phenom. The Socket AM2+ version of Phenom II was released in December 2008, while Socket AM3 versions with DDR3 support, along with an initial batch of triple- and quad-core processors were released on February 9, 2009.[1] Dual-processor systems will require Socket F+ for the Quad FX platform.[2] The Phenom II is the processor component of AMD's Dragon Platform, which also includes the 790 series chipset and Radeon HD 4800 series graphics. The Phenom II will also be the cpu in the upcoming Leo Platform which includes the AMD890 chipset and the Radeon HD 5800 series graphics. However the Phenom II that will be used in the Leo Platform will be the code-named "Thuban" core that features 6 cores whereas the CPU used in the "Dragon Platform" is the "Deneb" core that features 4 cores. The next generation cpu will be labeled the "Phenom II X6"



The Phenom II triples the shared L3 cache size from 2MB (in the original Phenom line) to 6MB,[3] leading to benchmark performance gains as high as 30%.[4] Another change from the original Phenom is that Cool 'n Quiet is now applied to the processor as a whole, rather than on a per-core basis. This was done in order to address the mishandling of threads by Windows Vista, which can cause single-threaded applications to run on a core that is idling at half its clock rate.[5]

Socket AM2+ versions of the Phenom II (920, 940) are not forwards-compatible with Socket AM3 [6]. Socket AM3 versions of the Phenom II are backwards-compatible with Socket AM2+, though this is contingent on motherboard manufacturers supplying BIOS updates. In addition to the Phenom II's pin compatibility, the AM3 memory controller supports both DDR2 and DDR3 memory (up to DDR2-1066 and DDR3-1333), allowing existing AM2+ users to upgrade their CPU without changing the motherboard or memory. However, similar to the way the original Phenom handled DDR2-1066, current Phenom II platforms limit the usage of DDR3-1333 to one DIMM per channel; otherwise, the DIMMs are underclocked to DDR3-1066.[7] AMD claims that this behavior is due to the BIOS, not the memory controller, and plans to address it with a BIOS update. The dual-spec memory controller also gives motherboard manufacturers and system builders the option of pairing AM3 with DDR2 to reduce overall system cost, as compared to competing chips from Intel, which require DDR3.

Some top-level AM3 processors (x945 125W, x955 and x965) require a special power supply feature, often called "dual power-plane". It's supported by default in all native AM3 mainboards, however not in most AM2+ mainboards, even those advertised as "AM3 optimized" or "AM3 ready". Processor running below it's nominal speed (i.e. at 800 MHz), clock and multiplier locked are symptoms of this incompatibility. This is a hardware issue, not resolvable via BIOS update[8].

AMD Phenom-based processor family
AMD K10 Desktop
Quad-core Triple-core Dual-core
AMD Phenom logo as of 2008 AMD Phenom logo as of 2009 AMD Phenom logo as of 2009 AMD Phenom logo as of 2009
Code-named Deneb Heka Callisto
Core 45 nm 45 nm 45 nm
Date released Feb 2009 Feb 2009 Jun 2009
List of AMD Phenom microprocessors

Beginning with the AM3 versions of the Phenom II, three series based on the same silicon are being marketed. The first series is the flagship representing the full performance potential of the chip. The other three series are formed by die harvesting, that is, chips that were produced with some amount of defects. The affected portions of these chips are disabled and the chips themselves marked as a lower-grade product.[1]

  • 900 series: Flagship series with full complement of cores and L3 cache enabled.
  • 800 series: These are chips with some amount of defect in the L3 cache; 2 MB is disabled, leaving the chip with 4 MB L3 cache and fully operational cores.
  • 700 series: These chips have one core disabled, leaving it with three operational cores (marketed as "X3") and a fully operational L3 cache.
  • 500 series: These chips have two cores disabled, leaving it with two operational cores (marketed as "X2") and a fully operational L3 cache.

There are some versions of the Phenom II X2 and X3, however, which have no defects in the silicon but one or two cores "deactivated" to enable AMD to target the lower end of the market[9]. As a result, with the correct motherboard and BIOS it is possible to unlock the deactivated core(s) of the processor. However, success is not guaranteed, because in some cases the core(s) may have been deactivated due to faulty silicon. Hardware enthusiast websites have collected and summarized anecdotal reports that, overall, indicate about a 70% success rate,[10] but these reports likely have self-reporting bias, and more importantly, it is impossible to know whether an unlocked core is truly bug-free or just works "well enough" for the particular individual making the report.


The Phenom II range of CPUs is the first series of AMD CPUs to eliminate the "Cold Bug" (which causes the processor to cease functioning below a certain temperature, and prevents the use of "extreme" cooling methods such as dry ice or liquid nitrogen). With the elimination of this cold bug, these CPUs are expected to overclock to much higher levels than any other AMD CPU range.[11][12]

In a public demonstration of the Phenom II's overclocking potential (Las Vegas 10 January 2009, CES 2009), Sami "Macci" Mäkinen (a record-breaking overclocker) used a Phenom II X4 940 and a DFI LANParty 790FXB-M2RS with a combination of liquid nitrogen and liquid helium cooling to take the processor to a clock rate of 6.5 GHz and succeeded in beating the world record 3DMark 2005 score with a total of 45474.[13][14]

A group named LimitTeam successfully overclocked AMD’s Deneb 45 nm Phenom II X4 955 processor (Black Edition) on April 30, 2009, and submitted the results for validation to CPU-Z. During the process, the group used the Asus M4A79T Deluxe motherboard, dubbed as the Asus “multidimensional performance platform” featuring support for an AMD 140W CPU and the AMD 790FX/SB750 chipset. As a result, the group reached 7.127 GHz, beating the previous score of 6.7 GHz. However, LimitTeam didn’t reveal any specifics in regards to cooling during the overclocking process.[15]






See also


  1. ^ a b
  2. ^ Anh Tuan Huynh (July 2, 2007). "AMD Second-Generation 'Stars' Plans Unveiled". DailyTech. Retrieved 2007-11-26. 
  3. ^
  4. ^
  5. ^
  6. ^
  7. ^
  8. ^
  9. ^
  10. ^ Anand Lal Shimpi (2010-01-28). "Unlocking the Phenom II X2 (see comments)". Retrieved 2010-01-30. 
  11. ^ AMD Shows Off Phenom II OverClocked to 6.3GHz
  12. ^ AMD's Phenom II Show Overclocking Potential
  13. ^ Patrick Moorhead (January 15th, 2009). "Breaking Records with Dragons and Helium in the Las Vegas Desert". Retrieved 2009-09-18. 
  14. ^ PC Perspective - 6.3GHz Phenom II Overclock on LN2
  15. ^ CPU clock beat up to 6.7 Ghz : only with AMD

External links


Got something to say? Make a comment.
Your name
Your email address