OBS Mac - HOW to stop EXCESSIVE GPU utilization

[thomaslfessler]

Problem: OBS on MacOS can easily overwhelm a powerful GPU. Researching the topic, I've read multiple issues in this forum from users with Retina 5K macs and various Apple Laptops that are easily overwhelmed. None of the messages provided a 'working solution' in part because those responding were probably not able to reproduce the problem... While there may be a 'code' based reason for this excessive resource utilization, yes this is a real bug, I've found a way to reduce GPU utilization locked up by OBS. Essentially a work around that should work for EVERYONE.

Findings: OBS GPU utilization is directly tied to size of the image rendered and pushed to the screen by MacOS - not the displayed resolution size. If you are using a 4K/5k monitor and are displaying a resolution with HiDPI enabled, Your GPU can be easily overwhelmed.

• 4K monitor setup with 4k HiDPI image ~ 65% GPU utilization with no activity in OBS.
• 4K monitor setup with 4k image, ~ 25% GPU utilization with no activity in OBS.
• 1080p monitor setup 1080p HiDPI Image ~ 25% GPU utilization with no activity in OBS.

Solution: Switch to a non-HiDPI resolution on your mac, using a utility such as SwitchRes-X, to greatly reduce GPU utilization, freeing up resources for other applications, etc.

Hope this helps -
Thomas

 

[kellemar]

How does this work for an external monitor setup? Assuming that both my laptop and external monitors are turned on at the same time.

 

[thomaslfessler]

How does this work for an external monitor setup? Assuming that both my laptop and external monitors are turned on at the same time.

Hmmm. Great question! Any Macbook with a Retina display is going to use HiDPI to increase the visual quality of the image for the integrated LCD. I would suggest making sure that HiDPI is disabled for the external display and using that for OBS.

If you open Activity Monitor on your Mac and press Command-4 it shows GPU history. The image below shows me opening OBS and the app sitting idle at 3840x2160 with OBS chewing up about 25% of the GPU. Jumping to 3841x2160 HiDPI, GPU utilization jumps to about 60%.

Switching resolutions, you should see a change to the GPU LOAD within a matter of seconds.

 

[kellemar]

Got it. THanks!

 

[BrooklynAngel]

Hmmm. Great question! Any Macbook with a Retina display is going to use HiDPI to increase the visual quality of the image for the integrated LCD. I would suggest making sure that HiDPI is disabled for the external display and using that for OBS.

If you open Activity Monitor on your Mac and press Command-4 it shows GPU history. The image below shows me opening OBS and the app sitting idle at 3840x2160 with OBS chewing up about 25% of the GPU. Jumping to 3841x2160 HiDPI, GPU utilization jumps to about 60%.

View attachment 64996
Switching resolutions, you should see a change to the GPU LOAD within a matter of seconds.

How do you switch resolutions?

 

[nottooloud]

How do you switch resolutions?

Post mentions SwitchRes-X.

 

[thomaslfessler]

How do you switch resolutions?

Here's a link to the Developer's Website.

SwitchResX - The Most Versatile Tool For Controlling Screen Resolutions On Your Mac

I've been using SwitchResX for too many years to count.

Once installed, you can choose a resolution that's not listed as HiDPI from the finder bar drop down menu.