Question / Help OBS pegs GPU just being open


New Member
I've been trying to record minecraft game play, but OBS is only recording about 3-5 fps. I have an egpu which minecraft is using, so it's not competing. When I open GPU History, I can see the internal GPU usage go to 100% as soon as I open OBS and before I even start recording. Is there a setting I have wrong? Here's my info.

2017 iMac, 32 GB Ram, Radeon Pro 575 4096 MB
egpu: Radeon RX 580

OBS v 23.1.0
Captures Tried with the same effect: Display Capture, Display Capture cropped to window, Window capture
Audio output capture (through soundflower)
Audio input capture

This is probably not THE problem, since I don't even have to hit record, but the record settings are:
Type: Standard
Format: mkv
2 audio tracks
rescale output to 2048x1152
Rate control: CRF
CRF: 21
Keyframe Interval: 0
CPU Usage Preset: veryfast
No profile, no Tune, no x264 Options

Log file from a short recording test attached.


  • 2019-05-20 21-10-48.txt
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Active Member
21:10:48.753: video settings reset:
21:10:48.753: base resolution: 5120x2880
21:10:48.753: output resolution: 5120x2880

Set that to something sane. There is no reason to capture the native resolution of a retina display, you're just going to see exactly what you're getting-- GPU pegged at 100% utilization forever.

Drop to 1920x1080 canvas resolution and output and see what happens.


New Member
Ah. Thanks.
I had the output scaled down, but didn't think of the base canvas resolution.

Unfortunately, changing the base resolution isn't helping any. The GPU is still pegged, and recordings are still only a few FPS


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    Untitled 4.png
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New Member
Blegh. If anything it's worse. Got seriously ill from the low FPS while playing. The game is nice and smooth without OBS open.


Active Member
If you've changed settings please upload another log, preferably one with a recording or streaming session in it.

Your screen capture shows scaling *down* to 2048x1152 which would indicate that your base canvas is still larger than that which probably means you haven't lowered it enough to give OBS the GPU headroom it needs to render frames (along with Minecraft).

I hope you've also specified a framerate cap in Minecraft, since you'll almost certainly need to do that as well.