Decreased game FPS during OBS screen capture.
Affected version
Arch Linux / Gnome 43.3 / Mutter 43.3-2 / Wayland
Bug summary
While playing a game there is a noticeable 20-30 FPS drop when OBS Studio is opened and captures the screen.
Steps to reproduce
- Have the latest Gnome / Mutter / Nvidia Drivers / OBS installed.
- Launch a game with an FPS counter to monitor FPS.
- Note the average FPS at any point.
- Launch OBS Studios.
- Capture the screen with the game running within OBS Studios.
- Note FPS drop.
- Turn off screen capture.
- FPS increases back to regular rates.
What happened
When I began a screen capture in OBS (not recording or streaming) for a videogame through Steam, I noticed a considerable 20-30 average drop in FPS. This is constant while the screen capture is ongoing. When the screen capture is ended or hidden, FPS rates return to average.
What did you expect to happen
I would expect a smaller drop in FPS if any for just screen capture.
Relevant logs, screenshots, screencasts etc.
I do not have much information regarding logs other than those I pulled from OBS for testing. I did test this in Arch Linux KDE Plasma with Wayland using the same PC / Drivers / Settings and only experienced a 1-3 FPS drop if any. I brought this problem to OBS Studios initially. Upon some testing, it was determined the OBS Studio was working as intended, and concluded the problem may be with Gnome / Mutter as that appears to be the differentiating factor in replicating the problem. I was then advised to submit this to Gnome. The following logs were made with the hardware noted and using the Nvidia-DKMS driver (525.89.02) with DRM kernel mode setting and early loading.
Gnome OBS log: https://obsproject.com/logs/5L5w69hS1vVthm7i
KDE Plasma OBS log: https://obsproject.com/logs/BO1pNFSPuvI3mIcF
If any additional information is needed, I am willing to help.