GPU Physics, PhysX and 3DMark Vantage
We believe physics simulation, whether performed on the CPU or the GPU, will be an increasingly important feature of upcoming games. The powerful parallel processing capabilities of modern GPUs have been proven to be very useful for accelerating some types of physics calculations, such as cloth simulations and rigid body collisions, used to enhance game visuals. However, using the GPU in this way only makes sense if it doesn't detract from graphics rendering performance. In other words, adding a few more moving objects into a scene isn't necessarily beneficial if it requires other 3D effects to be simplified, or sacrifices resolution and frame rate.
3DMark Vantage attempts to address the growing importance of game physics by including support for GPU-accelerated physics in the GPU tests, implemented using DirectX 10 geometry shaders. The developers balanced the physics and rendering workloads in a way they felt was reflective of what we would see in next-generation games. Additionally, they included CPU tests that supported the use of Ageia PhysX PPUs to offload some physics calculations from the CPU. This decision was made prior to the acquisition of Ageia by NVIDIA, and the subsequent discontinuation of discrete PPU products.
Recently released drivers from NVIDIA (ForceWare 177.39) fool the 3DMark Vantage benchmarks into thinking an Ageia PhysX PPU is installed, while actually doing the additional physics processing on the GPU. Since Vantage has separate GPU & CPU benchmarks which both include physics processing, this causes the performance benefits of GPU physics to be double-counted, resulting in an aritificial inflation of the final score. Real games can be expected to limit the amount of GPU physics processing to avoid significantly impacting rendering performance. Also, we are confident that the vast majority of upcoming game titles will not include support for PhysX, but will instead rely on more popular physics middleware (such as Havok) or proprietary physics engines, which will not benefit in any way from NVIDIA 's PhysX drivers.
Note section 3.5 of FutureMark’s 3DMark Vantage Driver approval policy states:
5. Based on the specification and design of the CPU tests, GPU make, type or driver version may not have a significant effect on the results of either of the CPU tests as indicated in Section 7.3 of the 3DMark Vantage specification and whitepaper.”
https://www.futuremark.com/companyinf...y_v100.pdf?m=v
According to FutureMark’s rules NVIDIA drivers that accelerate physics calculations by the GPU will not receive approval and hence are not valid drivers to use for comparison. 3DMark Vantage does have a “Disable PPU” option and utilizing this should more accurately reflect the scores FutureMark intended according to their rules when using NVIDIA ForceWare drivers that accelerate PPU calculations via the GPU under 3DMark Vantage.
We also advise testing boards at the level of ATI Radeon HD 4800 Series in the “High” and “Extreme” modes as these modes place a greater onus on the graphics processing capabilities of the GPU. “Performance” mode settings is more designed for mainstream level GPU’s.
المشاركة الأصلية كتبت بواسطة HD5870X2
رد: مجموعة اسئلة ATI PHYSX
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