This question was posted last week under SLI, but I don’t think it was the correct location to post, so I’m going to try GPU computing.
I’m currently writing some code to work with UAV’s for order independent transparency.
I’ve noticed that binding the UAV’s in dx11 using OMSetRenderTargetsAndUnorderedAccessViews with SLI enabled and windowed mode on causes significant performance degradation.
Judging from the SLI developer documentation from 3 years ago, I am guessing that I have to clear the UAV’s to some magical value in order to prevent them being copied over the sli bridge?
I have tried clearing the uav’s to 0 and MAX_UINT but the performance problem remains.
Is there a magical value I have to clear the UAV’s to?
Is this a known dx11 SLI bug?
Will the developer team be issuing a new “best practices guide” for SLI and the new fermi class hardware?
DX Compute does work with SLI. SLI almost always works in AFR (alternate frame rendering) mode these days, so you should get a speed up as long as your frames are completely independent.
It’s hard to say what your problem is without seeing the code. You can post here, or register as a developer and file a bug there.
DX Compute does work with SLI. SLI almost always works in AFR (alternate frame rendering) mode these days, so you should get a speed up as long as your frames are completely independent.
It’s hard to say what your problem is without seeing the code. You can post here, or register as a developer and file a bug there.
In my application I’m doing a much heavier render than this demo and I go from 90fps fullscreen 2560x1600 to 10fps windowed 640x480 with AFR2 and fractions of a frame (0.3 - 0.4) a second with AFR1.
If I disable SLI, I get about 110 fps in windowed with the same scene, but I am bound in other places at the moment too.
As I stated earlier, I think the performance regression can be tracked back to the call to SetRenderTargetsAndUndorderedAccessViews.
In my application I’m doing a much heavier render than this demo and I go from 90fps fullscreen 2560x1600 to 10fps windowed 640x480 with AFR2 and fractions of a frame (0.3 - 0.4) a second with AFR1.
If I disable SLI, I get about 110 fps in windowed with the same scene, but I am bound in other places at the moment too.
As I stated earlier, I think the performance regression can be tracked back to the call to SetRenderTargetsAndUndorderedAccessViews.