Working around poor display performance when folding

[csvanefalk]

I am folding on a Fedora 20 box, with a GTX770 running on the 319.76 drivers.

I did expect display performance to take a hit while folding and working at the same time, but it has become all but unworkable. The Xorg process shoots to 100% on the most minute screen updates (scrolling etc), and overall display performance is extremely laggy.

Are there any settings I can tweak in the client or the Nvidia driver settings to work around this? I know the Windows clients allow users to limit GPU usage, but this does not seem to exist for Linux.

[davidcoton]

There is no effective throttling for GPU usage in Linux or in Windows. The low-level scheduling of GPU tasks is not as sophisticated as for CPUs, and it is just not possible to assign priorities to GPU tasks. Once a task is queued, a later task cannot overtake it.

[csvanefalk]

Yes, my mistake. Not sure where I got that from.

Currently I have found a reasonable workaround by using software-rendered Cinnamon as my DE. No tearing for now - will see if it stays that way.

[bollix47]

Another setting to check that might help is hardware acceleration ... ensure it is disabled in your browser and for flash.

viewtopic.php?p=248300#p248300
viewtopic.php?p=251796#p251796

[bruce]

They're the same thing. Disabling hardware acceleration is the same as enabling software rendering. Since rendering the screen on the GPU requires that the processing of a block of FAH geometry must be completed before Cinnamon can gain access to the GPU, there will be noticeable lags, While in absolute terms, CPU rendering is slower, it does have the benefit of receiving immediate CPU attention and therefore faster completion.

If your system can accommodate multiple GPUs, connecting your monitor to and added old/slow GPU that doesn't fold might also be worthwhile, but that may not be worth the hassle when CPU rendering is already working.

[jrweiss]

At present I have my system set up with Virtu D-mode enabled. When I started GPU Folding on the 7750, I did a bit of experimenting and found that Virtu enabled resulted in a noticeable improvement in PPD, even if screen lag was still evident at times.

Has anyone set up their system so the monitor uses the embedded Intel GPU, while using a discrete GPU for Folding only? Any downsides for strict 2D, non-gaming use? Does Virtu I-mode help or hinder in that case, if it works at all?

[csvanefalk]

Thanks for the input so far - I am still running software rendered Cinnamon, and it is working beautifully. PPD sits comfortably at 110k, and the only lag issues I have had so far is light hackiness in the browser and YT videos, but everything else works perfectly.