GPU Cheatsheet - A History of Modern Consumer Graphics Processorsby Jarred Walton on September 6, 2004 12:00 AM EST
- Posted in
Below you can see our breakdown of the GPU guide for ATI video cards:
|ATI Craphics Chips Overview|
|DirectX 9 with PS2.0b and VS2.0 Support|
|X800 XT PE||R420||520||1120||16||1||6||256||256|
|X800 XT PE?||R423||520||1120||16||1||6||256||256|
|DirectX 9 with PS2.0 and VS2.0 Support|
|9800 Pro 128||R350/360||380||680||8||1||4||128||256|
|9800 Pro 256||R350/360||380||700||8||1||4||256||256|
|9800 SE 128||R350||325||580||8||1||4||128||128|
|9800 SE 256||R350||380||680||4||1||4||128||256|
|DirectX 8.1 with PS1.4 and VS1.1 Support|
|* RAM clock is the effective clock speed, so 250 MHz DDR is listed as 500 MHz.|
|** Textures/Pipeline is the number of unique texture lookups. ATI has implementations that can lookup 3 textures, but two of the lookups must be from one texture.|
|*** Vertex pipelines is estimated on certain architectures. NVIDIA says their GFFX cards have a "vertex array", but in practice it performs as shown.|
|^ Radeon 7000 and VE Series had their Transform and Lighting Engine removed, and hence cannot perform fixed function vertex processing.|
As far as the various models are concerned, ATI has DX7, DX8.1, and DX9 parts, as well as an unofficial DX9 with SM2.0b support - unofficial due to the fact that Microsoft has not actually certified this "in between" version of DX9. ATI has features that are part of SM3.0, but they do not include the full SM3.0 feature set. When they enable their 2.0b features, they fail WHQL compliance. Since not having WHQL compliance creates concerns among users (the dreaded "This device driver is not certified for use by Microsoft" warning), ATI will turn them off by default, and many people will not know enough to reenable them. It may not seem like a big deal, but software companies are less likely to optimize for non-standard features - especially ones that are disabled by default - so SM3.0 is more likely to see support than SM2.0b.
Generalizing somewhat, we can say that each family of ATI cards outperforms the older generation cards. There are, of course, exceptions, such as the 9550/9600 SE cards which are outclassed by the older 8500/9100 models, and the performance of the 9200SE is rather anemic in comparison to the 7500 in the majority of games. However, the added features and performance tweaks usually make up for the difference in raw numbers, and so comparing performance between the various generations of hardware does not always work.
Older ATI cards lacked support for multi-sample antialiasing, resorting to super-sampling as an alternative. Super-sampling, if you don't know, simply renders the screen at a higher resolution and then filters it down to a lower resolution, and in most cases it is limited to a maximum of 1600x1200. The quality is actually quite good with super-sampling, but the performance hit is enormous. Only with the R3xx cores did ATI begin to support multi-sampling, which helps to these cards to beat the previous generation when AA is enabled. Of course, once ATI did begin supporting multi-sampling, they did it very well, and the quality of their rotated grid sampling was regarded as being superior to the NVIDIA FX line.
ATI has also done anisotropic filtering very well for quite some time, although many believe it is due to "cheats" or "unfair optimizations". The real difference between ATI's implementation of AF and NVIDIA's is that ATI used a faster distance calculation. "True" anisotropic filtering does not really exist as such, and in the end it really comes down to getting improved image quality without killing performance. Today, it is very difficult to distinguish between the optimized and unoptimized filtering methods that both companies employ, and ATI has said they will address any situations where their image quality suffers.
At present, it is worth mentioning that all of the 9800 series chips and X800 series chips use the same base core. ATI validates the chips and in cases where portions of the chips fail, they can deactivate some of the pipelines and still sell the chip as a "light" version. With the 9800 SE cards, some people were able to "soft mod" their chips into full 9800 Pro cards, but success was not guaranteed. There are rumors that the same can be done with the X800 Pro cards, although success seems to be relatively rare right now, likely due to the large size of the chips. As the manufacturing process improves, success rates should also improve, but it's still a gamble. 9500/Pro cards were also based off the more complex 9700/Pro chip, and quite a few people were able to mod these cards into faster versions, but the introduction of the 9600 series put an end to that. We do not recommend purchasing the lower end cards with the intent to soft mod unless you are willing to live with the consequences, namely that success is by no means guaranteed and it will void the warranty. In our opinion, the relatively small price difference just isn't enough to warrant the risk.