Spike in CPU usage on Intel when upgrading to 2.3.8 and using a virtual screen

[nuTTeLLo]

There is a huge spike in CPU usage when upgrading from 2.3.7 to 2.3..8.

Notice that the WindowServer process CPU usage goes up to 300-400% and the colorsync.useragent process suddenly just starts going up to 40-50% CPU usage when using 2.3.8. This makes the computer almost unusable. Was never this issue on 2.3.7 (WindowServer process generally around the below 100% CPU usage mark).

Using a 2019 Macbook Pro with two attached monitors and an Virtual Screen mirrored to an iPad.

[vincetran96]

There is a huge spike in CPU usage when upgrading from 2.3.7 to 2.3..8.

Notice that the WindowServer process CPU usage goes up to 300-400% and the colorsync.useragent process suddenly just starts going up to 40-50% CPU usage when using 2.3.8. This makes the computer almost unusable. Was never this issue on 2.3.7 (WindowServer process generally around the below 100% CPU usage mark).

Using a 2019 Macbook Pro with two attached monitors and an Virtual Screen mirrored to an iPad.

How long did the spike last? I have been experiencing huge, short (about 1-2 seconds) spikes in CPU usage recently, after installing and trying BetterDisplay, among some other apps. As I'm not sure which app has been causing the spikes, I have tried quitting all of my recently installed ones, except BetterDisplay, and still got those spikes. This led me to the issue tracking page and I just found this one.

If if matters, my hardware is

• Macbook Pro 14" 2021
• CPU: Apple M1 Pro
• OS: MacOS Sonoma 14.5

BetterDisplay version: 2.3.8

[waydabber]

Hi @nuTTeLLo,

sorry about the issue with the virtual screen. Some questions:

• If you start the app with logging from Terminal, do you see any special continuous activity/log output? /Applications/BetterDisplay.app/Contents/MacOS/BetterDisplay -v
• Does this issue go away if you downgrade to v2.3.7?

The only colorsync related change in v2.3.8 was #3137. The change however should not cause a sustained CPU usage in colorsync.useragent.

@vincetran96 - you should check Activity Monitor and see which apps are causing the spike. One rare reason how it could be related to BetterDisplay is the XDR upscaling feature, which puts the screen into EDR (HDR) mode for extra brightness. If auto brightness (ambient light sensor) is enabled and the brightness conditions vary, this can cause extra CPU usage on some apps as the system might ask various apps to re-tonemap HDR content as the brightness changes. If this happens continually, that puts some extra burden on these apps. To avoid this, you can use native XDR upscaling (select the BetterDisplay XDR preset under XDR Presets & Brightness) instead of the default software XDR upscaling or simply turn off auto brightness (or disable software XDR upscaling).

[waydabber]

@nuTTeLLo - are you on Ventura or Sonoma?

[waydabber]

Nvm, was able to reproduce the issue on Intel Macs both on Ventura and Sonoma. Apparently simply enabling a virtual screen will trigger and endless ColorSync repository update cycle on Intel. :(

I'll fix this issue in an update.

[waydabber]

I posted a v2.3.9 update as this issue seems to be a severe one that potentially affects many Intel configurations.

[Adrian-at-IB]

Thanks for the quick fix. Works well with 2.3.9.