Bug Report OBS wasting GPU power!

[Enes Altınkaya]

Hi, thanks for the awesome project!

Discovered this problem while playing Skyrim.
I've been playing for quite a while without issues.
Alt tabbing doing other stuff and going back to game.
At one point my game started lagging and i tried and found the cause.
It was OBS being open.

1 Scene - 1 Source, Screen Capture (XSHM)
Sitting there not recording, using %20 of the GPU.
Its a Gefore 780 TI.

I tried disabling preview as it looked like the cause, but it only made %2-3 difference.
Here are the screenshots and the log.

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[Harold]

There's a difference between "wasting" and "using"

OBS uses the GPU for scene composition.

 

[c3r1c3]

You DO realize that OBS uses your GPU for compositing your scenes? (and not your CPU which saves on cycles so you can compress your stuff).

Also that OBS (unlike Skyrim) is natively using OpenGL and Linux level syscalls?

Also that Linux doesn't have any type of efficient game capture mode?

And that some of this depends on different configuration options that no one has explored in depth in Linux-land (let alone OBS+Linux-land).

All of that said, you can file a bug report at www.obsproject.com/mantis and supply your logs and system logs and pics to see if it can be fixed.

 

[Enes Altınkaya]

Well, if you want to run OBS to record any game play, %20 of the GPU is wasted.

 

[c3r1c3]

Also, just ran some tests on my Linux box (NVidia GT730), and XSHM (basically Display Capture in Windows and MacOS) has always been the least efficient/worst way to capture stuff.

Window capture (xcomposite) took almost no GPU (about 2-3%), where as XSHM took close to 50%.

 

[c3r1c3]

No... it's that you are intentionally using an inefficient OS (Linux+X-Windows), with the worst possible capture method.

As to OBS using your GPU, if you don't like your GPU being used, then don't run OBS. Use a different program, one that composites your scenes on your CPU... and enjoy the serious CPU hit.

Also note that you can disable the preview, but I'm not sure if that will save you any GPU usage.

 

[Enes Altınkaya]

I could use SimpleScreenRecorder with nvenc_hevc codec and it would do the job.
But i like OBS better. I want to use it and support it.

 

[c3r1c3]

I understand. I use OBS on Linux as well. Linux in the graphics (i.e. X-wIndows+Window Manager+Desktop Environment) department just isn't nearly as good Windows or MacOS. Basically Display Capture on Linux is worse then Display Capture on Windows 7 with Aero enabled.... Hmm.. I wonder if it's the same issue on the backend...

There isn't a fix that OBS can really do. Wayland looks to be a huge help/step forward, but no idea when the dust will settle around it and it'll be bug/crash-free enough for people to use.

The best thing is to use Window capture (xcomposite) where ever you can... even if that means running your game in a window, until the Linux-GUI crowd (or the OBS team if it's possible) figure out how to have a mem copy that isn't dropping down to the CPU.