Originally posted by bug77
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NVIDIA Lands Fix To Avoid High CPU Usage When Using The KDE Desktop
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I don’t buy this. __GL_MaxFramesAllowed has never been there before as an option, it’s brand new. And the KWIN_TRIPLE_BUFFER option does not cause kwin to use triple buffering. No, enabling it tells kwin “the nvidia OpenGL implementation is mandating triple buffering, so work around it.” Up until this point, the only methods nvidia made available to not let the driver queue extra frames and increase input lag significantly had the side effect of a busy wait and 100% CPU.
This mandatory triple buffering is a bad driver optimization trick to increase FPS numbers at the cost of latency. The nvidia drivers in Windows do it, too. If __GL_MaxFramesAllowed works like it’s supposed to, 1 should be the default.
I’ve used only nvidia cards for 2 decades, and I always thought something strange was up with this. It was only after buying a cheap AMD card to try the new open source drivers that I finally knew that NVIDIA cards had more input lag. I suspect this is a side effect of the way the hardware operates, and that deficiency is also the reason that they can only do a Wayland implementation with non-coherent buffers.
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Originally posted by aufkrawall View PostAfaik the frame output delay isn't higher with Nvidia on Gnome (both Xorg and Wayland). It's "just" extremely stuttery on Xorg as soon as anything is going on in more windows than one, while this is no problem at all with Mesa.
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Originally posted by skeevy420 View Post
Yeah, I noticed after I posted that that sudo didn't pick up some variables that were in set in ~/.profile, sourced by .bashrc, and ended up hacking them into /etc/environment. It would probably make sense to put variables like these one into an early sourced file like environment as well. I assume it makes sense to put something that effects a graphics driver and a window manager in pretty early.
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Originally posted by bearoso View PostI don’t buy this. __GL_MaxFramesAllowed has never been there before as an option, it’s brand new. And the KWIN_TRIPLE_BUFFER option does not cause kwin to use triple buffering. No, enabling it tells kwin “the nvidia OpenGL implementation is mandating triple buffering, so work around it.” Up until this point, the only methods nvidia made available to not let the driver queue extra frames and increase input lag significantly had the side effect of a busy wait and 100% CPU.
This mandatory triple buffering is a bad driver optimization trick to increase FPS numbers at the cost of latency. The nvidia drivers in Windows do it, too. If __GL_MaxFramesAllowed works like it’s supposed to, 1 should be the default.
I’ve used only nvidia cards for 2 decades, and I always thought something strange was up with this. It was only after buying a cheap AMD card to try the new open source drivers that I finally knew that NVIDIA cards had more input lag. I suspect this is a side effect of the way the hardware operates, and that deficiency is also the reason that they can only do a Wayland implementation with non-coherent buffers.
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Originally posted by bearoso View PostI don’t buy this. __GL_MaxFramesAllowed has never been there before as an option, it’s brand new.
A 9 year old mention of MaxFramesAllowed?
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Originally posted by RealNC View PostIt incurs extra input lag, so it's not a good solution.
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