NVIDIA said that compiler technology tunes DirectX 9.0 execution on GeForce FX GPUs, and can be used to correct any similar conflict that arises with future APIs. NVIDIA indicated that the Unified Compiler is an automatic tuning tool that optimizes Pixel Shader performance on all applications, not just on specific ones.Source: X-bit Labs
However, it appears that some technical specialists have something to say against the new patch. Hans-Wolfram Tismer, a Managing Director for Gainward Europe GmbH said today: “According to my information patch 340 disables the GPU compiler. The compiler has to run on the CPU instead resulting in code harder to digest and taking away 20% of the performance. This may not reflect gaming performance and may point in the wrong direction. To me 3DMark03 may look less and less suitable to be used for benchmarking. By the end of the day the end users are running games and applications, not 3DMark03.”
Update: Beyond3D has also investigated NVIDIA and ATi his results before and after applying the new 3DMark03 patch. First they compare the scores and they also do some image quality comparisons. They found out that there is only a small difference in image quality :
Many of the image differences displayed here are fairly small and wouldn't be noticeable in play - its only with the use of a comparison tool that we can highlight where the image differences are. However, clearly there is differnces in the rendering of 3DMark03 under the 330 and 340 patch on the GeForce FX. Given the nature of the patch in what is was primarily designed for and what has changed, it would certainly seem that these rendering differences are as a result of shader replacements - the shader compiler optimiser that is featured in the 52.16 driver should not alter the image in in fashion.The test can be found here