AndrewCross
16-Jul-2008, 19:50
All,
We have run into a major performance problem on Vista that I am hoping that others here might have seen and know the solution for. Basically we are using the GPU for tasks that require the rendered data to be read back into system memory. To do this we use GetRenderTargetData(...). Now, when we run this using Windows XP, we see perfectly acceptable performance, but using Vista on the exact same application the performance is absolutely dismal. We have tried this on numerous different graphics cards from different manufacturers, different CPUs and chipsets and with different drivers and across all combinations continue to see the same problem. As an example, using a mid-range nVidia card you can get a download rate of about 1200Mb/s on Windows XP but only 200Mb/s on Windows Vista.
It is actually pretty easy to reproduce this, all you need to do is download the application below and it will exhibit this behavior in every situation we have tested.
http://www.seriousmagic.com/3D-DloadBenchmark.zip
Although this is a old DX applcation, we have confirmed the same results using our own code using DirectX9 and DirectX9Ex (on Vista).
It would seem to me that there must be some obvious explanation for this because it basically renders GPGPU applications completely useless on Vista.
Thanks in advance for any help.
Andrew Cross, Ph.D
VP of Software Engineering,
NewTek, www.newtek.com
We have run into a major performance problem on Vista that I am hoping that others here might have seen and know the solution for. Basically we are using the GPU for tasks that require the rendered data to be read back into system memory. To do this we use GetRenderTargetData(...). Now, when we run this using Windows XP, we see perfectly acceptable performance, but using Vista on the exact same application the performance is absolutely dismal. We have tried this on numerous different graphics cards from different manufacturers, different CPUs and chipsets and with different drivers and across all combinations continue to see the same problem. As an example, using a mid-range nVidia card you can get a download rate of about 1200Mb/s on Windows XP but only 200Mb/s on Windows Vista.
It is actually pretty easy to reproduce this, all you need to do is download the application below and it will exhibit this behavior in every situation we have tested.
http://www.seriousmagic.com/3D-DloadBenchmark.zip
Although this is a old DX applcation, we have confirmed the same results using our own code using DirectX9 and DirectX9Ex (on Vista).
It would seem to me that there must be some obvious explanation for this because it basically renders GPGPU applications completely useless on Vista.
Thanks in advance for any help.
Andrew Cross, Ph.D
VP of Software Engineering,
NewTek, www.newtek.com