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Old 10-27-09, 12:11 PM   #3
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Join Date: May 2003
Posts: 191
Default Re: VSYNC Frame Counter

Originally Posted by Paul1492 View Post
Who mantains the VSYNC Frame Counter? Is it determined in the driver alone or is it maintained on the video card?

I'm trying to use glXWaitVideoSyncSGI(..,..,&count). I'm running at 60Hz, but when I look at "count" at 100ms since the last time I checked it, it simply is one more than last time.

During this 100ms, I'm either retrieving a texture from the GPU (and pulling to the CPU) or storing a texture on the GPU (from the CPU).

I would have expected the GPU to still increment this frame count (multiple times) even if I'm keeping the driver busy with something.

I have a G-SYNC card and tried glXQueryFrameCountNV() but it seems to be returning garbage for the frame count.

Am I missing something?

I'm using a Quadro FX 5600 with 185.18.14. I see 185.18.31 fixes some other glXWaitVideoSyncSGI problem. I'll get a sys-admin to install this driver but will it fix this problem?
The two counts (from glXWaitVideoSyncSGI() and glXQueryFrameCountNV()) are unrelated. The former is only valid for a single monitor, while the latter gets its count from the gsync hardware and is valid across your entire framelock cluster. However, you need to enable framelock in nvidia-settings for the count from glXQueryFrameCountNV() to change (otherwise, it will remain constant).
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