Radeon R200: Wikis

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Radeon 8500 - 9250 Series
8500logo.png
Codename(s) Chaplin
Created in year Late 2001
Entry-level cards 9200SE
Mid-range cards 9000, 9200, 9250, 8500LE/9100
High-end cards 8500
Direct3D support 8.1, Shader Model 1.4
Predecessor Radeon 32/64,
Radeon 7000 series
Successor Radeon 9500-X600 series
Radeon R200-based chipsets
CPU supported Pentium M, Pentium 4-M
Socket supported Socket 478, Socket 479
Desktop / mobile chipsets
Performance segment 9100 Pro IGP
Mainstream segment 9000/9100 IGP
Value segment 9000 Pro IGP
Miscellaneous
Release date(s) June 23, 2003
May 5, 2004 (9000/9100 Pro IGP)
Predecessor Radeon 300/Mobility Radeon 7000 series IGP
Successor Radeon 9500 - X600 Series

The Radeon R200 is the second generation of Radeon graphics chips from ATI Technologies. The architecture features 3D acceleration based upon Microsoft Direct3D 8.0 and OpenGL 1.3, a major improvement in features and performance compared to the preceding Radeon R100 design. The GPU also includes 2D GUI acceleration, video acceleration, and multiple display outputs. "R200" refers to the development codename of the initially released GPU of the generation. It is the basis for a variety of other succeeding products.

Contents

Architecture

R200's 3D hardware consists of 4 pixel pipelines, each with 2 texture sampling units. It has 2 vertex shaders and a legacy Direct3D 7 TCL unit, marketed as Charisma Engine II. It is ATI's first GPU with programmable pixel and vertex processors, called Pixel Tapestry II and compliant with Direct3D 8.1. R200 has advanced memory bandwidth saving and overdraw reduction hardware called HyperZ II that consists of occlusion culling (hierarchical Z), fast z-buffer clear, and z-buffer compression. The GPU is capable of dual display output (Hydravision) and is equipped with a video decoding engine with hardware deinterlacing.

R200 introduced pixel shader version 1.4 (PS1.4), a significant enhancement to prior PS1.x specifications. Notable instructions include "phase", "texcrd", and "texld". The phase instruction allows a shader program to operate on two separate "phases" (2 passes through the hardware), effectively doubling the maximum number of texture addressing and arithmetic instructions, and potentially allowing the number of passes required for an effect to be reduced. This allows not only more complicated effects, but can also provide a speed boost by utilizing the hardware more efficiently. The "texcrd" instruction moves the texture coordinate values of a texture into the destination register, while the "texld" instruction will load the texture at the coordinates specified in the source register to the destination register.

Compared to R100's 2x3 pixel pipeline architecture, R200's 4x2 design is more robust despite losing one texture unit per pipeline. Each pipeline can now address a total of 6 texture layers per pass. The chip achieves this by using a method known as 'loop-back'. Increasing the number of textures accessed per pass reduces the number of times the card is forced into multi-pass rendering.

The texture filtering capabilities of R200 are also improved over its predecessor. For anisotropic filtering, Radeon 8500 uses a technique similar to that used in R100, but improved with trilinear filtering and some other refinements. However, it is still highly angle-dependent and the driver sometimes forces bilinear filtering for speed. NVIDIA's GeForce 4 Ti series offered a more accurate anisotropic implementation, but with a greater performance impact.

R200 has ATI's first implementation of a hardware-accelerated tessellation engine (a.k.a. higher order surfaces), called Truform, which can automatically increase the geometric complexity of 3D models. The technology requires developer support and is not practical for all scenarios. It can undesirably round-out models. As a result of very limited adoption, ATI dropped TruForm support from its future hardware.

DirectX 8.0
Pixel Shader 1.1
DirectX 8.1
Pixel Shader 1.4
Max. Texture Inputs 4 6
Max. Program Length 12 instructions
(up to 4 texture sampling, 8 color blending)
22 instructions
(up to 6 texture sampling, 8 texture addressing, 8 color blending)
Instruction Set 13 address operations, 8 color operations 12 address / color operations
Texture Addressing Modes 40 virtually unlimited

Performance

Radeon 8500's biggest disappointment was its early driver releases. At launch, the card's performance was below expectations and it had numerous software flaws that caused problems with games. The chip's anti-aliasing support was only functional in Direct3D and was very slow. To dampen excitement for 8500, competitor nVidia released their Detonator4 driver package on the same day as most web sites previewed the Radeon 8500. nVidia's drivers at the time were of better quality, and they also further boosted the GeForce 3's performance.

Several hardware review sites discovered that the performance of the Radeon 8500 in some actual game tests was lower than benchmarks reflected. For example, ATI was detecting the executable "Quake3.exe" and forcing the texture filtering quality to much lower than normally produced by the card. HardOCP was the first hardware review web site to bring the issue to the community, and proved its existence by renaming all instances of "Quake" in the executable to "Quack."[1] The result was improved image quality, but lower performance.

However, even with the Detonator4 drivers, the Radeon 8500 was able to outperform the GeForce 3 (which the 8500 was intended to compete against) and in some circumstances its faster revision, the Ti500, the higher clocked derivative Nvidia had rolled out in response to the R200 project. Later, driver updates helped to further close the performance gap between the 8500 and the Ti500, while the 8500 was also significantly less expensive and offered additional multimedia features such as dual-monitor support.

Implementations

Ati Radeon 9250

ATI's first R200-based card was the Radeon 8500, launched in October 2001. In early 2002, ATI launched the Radeon 8500LE (re-released later as the Radeon 9100), an identical chip with a lower clock speed and slower memory. Whereas the full 8500 was clocked at 275 MHz core and 275 MHz RAM, the 8500LE was clocked more conservatively at 250 MHz for the core and 200 or 250 MHz for the RAM. Both video cards were first released in 64 MiB DDR SDRAM configurations; the later 128 MiB Radeon 8500 boards received an small performance boost resulting from a memory interleave mode.

In November 2001 was the release of the All-In-Wonder Radeon 8500 DV, with 64 MiB and a slower clock speed like the 8500LE. In 2002, three 128 MiB cards were rolled out, the Radeon 8500, 8500LE, and the All-In-Wonder Radeon 8500 128 MB, which was clocked at full 8500 speeds but had fewer video-related features than the AIW 8500 DV.

The Radeon 9000 (RV250) was launched alongside the Radeon 9700. The 9000 succeeded the Radeon 7500 (RV200) in the mainstream market segment, with the latter being moved to the budget segment. This chip was a significant redesign of R200 to reduce cost and power usage. Among hardware removed is one of the two texture units, the "TruForm" function, Hierarchical-Z, the DirectX 7 TCL unit and one of the two vertex shaders. In games, the Radeon 9000 performs similarly to the GeForce 4 MX 440. Its main advantage over the MX 440 was that it had a full DirectX 8.1 vertex and pixel shader implementation. While the 9000 was not quite as fast as the 8500LE or the Nvidia GeForce 3 Ti200, the 8500LE and Ti200 were to be discontinued.

A later revision of the 9000 was the Radeon 9200 (RV280), which aside from supporting AGP 8X, was identical. There was also a cheaper version, the 9200SE, which only had a 64-bit memory bus. Another board, called the Radeon 9250 was launched in summer 2004, being simply a lower-clocked RV280.

Mobility

The Mobility Radeon 9000 was launched in early summer 2002 and was the first DirectX 8 laptop chip. It outperformed the DirectX 7-based nVidia GeForce 2 Go and was more feature-rich than the GeForce 4 Go.

A Mobility Radeon 9200 later followed as well, derived from the desktop 9200.

Models

Drivers

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UNIX-related operating systems

ATI has released no driver support for BSD based operating systems, however they do provide drivers for the X Window System running on Linux. Despite this, newer ATI Catalyst driver for Linux X Window System does not offer support for any R200 or older architecture product. Users are referred to using older drivers for older kernels, or the open source "radeon" driver for newer kernels. The PowerPC-based Mac mini and iBook G4, which run on Mac OS X, were supplied with Radeon 9200 cards.

Some segments of the Linux user community, which prefer to avoid the IP-encumbered ATI drivers due to stability and long term maintainability reasons, still prefer the R200-based chips, as they are among the fastest modern video cards with stable open source 3D drivers.

Windows drivers

This series of Radeon graphics cards is supported by AMD under Microsoft Windows operating systems including Windows XP (except x64), Windows 2000, Windows Me, and Windows 98. Other operating systems may have support in the form of a generic driver that lacks complete support for the hardware. Driver development for the R200 line ended with the Catalyst 6.11 drivers for Windows XP.

See also

References

  1. ^ Bennett, Kyle. Optimizing or Cheating Radeon 8500 Drivers, Hard OCP, October 23, 2001.

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