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Old 01-14-11, 04:56 PM   #8
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Join Date: Jan 2011
Posts: 1
Default Re: glX VSYNC does not work with ACER GD245HQ

I have been fighting the same symptoms with the same monitor, but on Windows (Win7). The SwapBuffers update rate seems to be ever so slightly different from the display vertical sync. I am displaying alternate frames of a stereo pair, and every few seconds, the right-left sync reverses.

Further, with shutter glasses synced with the SwapBuffers call, shows the frames gradually drifting out of sync during each two or three-second cycle.

I recognize that SwapBuffers merely schedules the actual swap, but I don't think I would be seeing the gradual shift of the display unless the actual frequency of my SwapBuffer calls did not match the physical refresh on the display itself.

Is it possible that the NVidia driver or hardware (GEForce 240) is somehow decoupled from the display and is free running at close to, but not locked at, its actual refresh?

Johann, did you ever resolve this issue?

Oh, I have also attempted to synchronize via Direct3D getRasterStatus scanline tracking. The exact same symptoms result.

Any clues for solving this?
thorolson is offline   Reply With Quote