msxyz
11-07-04, 11:07 AM
Ok, this week I had some spare time on my side and I finally performed some experiments I had in mind for a while...
Since Doom3 supports multiple render paths, involving the use of different pixel shader instruction sets, I made some comparison between them. I was particulary interested in ARB2 vs NV20 path performance on NV3x hardware. I happened to have one spare NV34 (a XFX GeForce5500) so I could also benchmark my NV36 card against the "older generation" NV34 core. The results are interesting.
Test metodology: Detonator 65.73, Quality settings, no trilinear optimizations. Doom3: high quality, 1024x768, Anisotropic filtering disabled. I used a custom timedemo recorded from the intro scene (1785 frames). Tests repeated 5 times, I dropped the highest and lowest value and made the average from the remaining three...
I've also tested NV10 and ARB paths but I don't feel they're interesting to my research. Instead, I concentrated on the ARB2 vs NV20 path comparison because they are both usable on the NV3x hardware and they look quite similar.
Now, to the numbers...
GeForceFX5500 (270MHz core / 200 MHz DDR)
ARB2 path: 12.0 fps ; NV20 path: 14.0 Difference +16.6%
Shadows/Advanced SFX disabled:
ARB2 path: 18.7 fps ; NV20 path: 23.5 Difference +25.6%
My comment: On the NV34, the NV20 path is much faster than the ARB2 path, despite the fact that it requires multiple passes to render the frame. I was expecting such results, but the gap really impressed me. If any of you has a low-end 5200/5600 on your PC and wants to play Doom3, the NV20 path may be a better solution. The NV20 path does not support the "heat haze" effect and it has a slightly worse image quality but it may be a better compromise than reducing texture quality or disabling some features. PS: As you can see, a GeForceFX5500 is not the ideal card to play Doom 3 at 1024x768! :)
GeForceFX5700U (475MHz core / 450 MHz DDR)
ARB2 path: 25.2 fps ; NV20 path: 24.3 Difference -3.5%
Shadows/Advanced SFX disabled:
ARB2 path: 32.4 fps ; NV20 path: 29.9 Difference -7.7%
My Comment: on the NV36, it seems that switching from the ARB2 to the NV20 path will cause a little performance drop. NVidia did redesign the NV35/6 core to boost its performance with PS2.x shaders. Using the NV20 render path on a GeForce 5700/5900 affects both performance and quality in a negative way.
Well, these are my findings. I do not claim them to be 100% accurate. Both cards were probably held back by my slow CPU. I wish I had a FX5600 and a FX5800 to throw into the test. Maybe some of you can try and see if the results are similar
Since Doom3 supports multiple render paths, involving the use of different pixel shader instruction sets, I made some comparison between them. I was particulary interested in ARB2 vs NV20 path performance on NV3x hardware. I happened to have one spare NV34 (a XFX GeForce5500) so I could also benchmark my NV36 card against the "older generation" NV34 core. The results are interesting.
Test metodology: Detonator 65.73, Quality settings, no trilinear optimizations. Doom3: high quality, 1024x768, Anisotropic filtering disabled. I used a custom timedemo recorded from the intro scene (1785 frames). Tests repeated 5 times, I dropped the highest and lowest value and made the average from the remaining three...
I've also tested NV10 and ARB paths but I don't feel they're interesting to my research. Instead, I concentrated on the ARB2 vs NV20 path comparison because they are both usable on the NV3x hardware and they look quite similar.
Now, to the numbers...
GeForceFX5500 (270MHz core / 200 MHz DDR)
ARB2 path: 12.0 fps ; NV20 path: 14.0 Difference +16.6%
Shadows/Advanced SFX disabled:
ARB2 path: 18.7 fps ; NV20 path: 23.5 Difference +25.6%
My comment: On the NV34, the NV20 path is much faster than the ARB2 path, despite the fact that it requires multiple passes to render the frame. I was expecting such results, but the gap really impressed me. If any of you has a low-end 5200/5600 on your PC and wants to play Doom3, the NV20 path may be a better solution. The NV20 path does not support the "heat haze" effect and it has a slightly worse image quality but it may be a better compromise than reducing texture quality or disabling some features. PS: As you can see, a GeForceFX5500 is not the ideal card to play Doom 3 at 1024x768! :)
GeForceFX5700U (475MHz core / 450 MHz DDR)
ARB2 path: 25.2 fps ; NV20 path: 24.3 Difference -3.5%
Shadows/Advanced SFX disabled:
ARB2 path: 32.4 fps ; NV20 path: 29.9 Difference -7.7%
My Comment: on the NV36, it seems that switching from the ARB2 to the NV20 path will cause a little performance drop. NVidia did redesign the NV35/6 core to boost its performance with PS2.x shaders. Using the NV20 render path on a GeForce 5700/5900 affects both performance and quality in a negative way.
Well, these are my findings. I do not claim them to be 100% accurate. Both cards were probably held back by my slow CPU. I wish I had a FX5600 and a FX5800 to throw into the test. Maybe some of you can try and see if the results are similar