WindowServer jumps to 40+% usage with Thunderbolt external display

Question

Level 1

12 points

WindowServer jumps to 40+% usage with Thunderbolt external display

I have a MacBook Air 13" Mid 2012, running OS X 10.10 Yosemite, with a Thunderbolt Display 27". When plugged into the external display, the WindowServer process jumps to 40% usage at the minimum (was holding steady at 70% until I restarted and chose not to reopen apps). When not plugged into the Thunderbolt Display, WindowServer clocks in at <1% usage. I don't recall this happening on Mavericks or any previous OS X. This cannot be expected behavior, right?

Posted on Oct 17, 2014 6:56 PM

Reply

Answer 1

Wingsy

Level 2

210 points

Oct 18, 2014 4:50 AM in response to ivanbe

Sorry but I can't help you, since I have a similar problem with WindowServer myself. Running nearly anything causes WS to go ballistic, slowing my system down for everything. This started as soon as Yosemite was installed. Also, on every boot I see a progress bar during startup (before the desktop) and it takes much longer to boot up now. I've read of similar problems with WS back during the beta testing of Yosemite but it appears Apple hasn't yet fixed the problem for everyone. I guess I'll limp along until the next update. We can only hope.

Reply

Answer 2

RickAce

Level 1

4 points

Oct 18, 2014 9:54 AM in response to Wingsy

I'm having the same identical issue (external monitor Viewsonic VX2025wm Display 20-inch (1680 x 1050))...

Reply

Answer 3

xythobuz

Level 1

0 points

Oct 18, 2014 10:05 AM in response to Wingsy

Same problem here, WindowServer using too much CPU. I don't have a Thunderbolt Port, but it also seems to be related to my external display (mini display port).

Reply

Answer 4

ivanbe Author

Level 1

12 points

Oct 18, 2014 10:40 AM in response to Wingsy

Yeah, I also see the progress bar at login when plugged into the external display. The wake up/login process is sort of hinky in general, which I'd attributed to the poor performance issues I'm experiencing elsewhere in Yosemite.

Reply

Answer 5

Humbs

Level 1

10 points

Nov 3, 2014 6:53 PM in response to ivanbe

Hi, try this: Disable the "Display have separate Spaces" in Mission Control

LogOff and Login again, check the process...

all fine?

Reply

Answer 6

ivanbe Author

Level 1

12 points

Nov 5, 2014 1:44 PM in response to Humbs

Humbs — this did seem to help tremendously. Although I have been using Spaces regularly in a multi-screen setup, I'm willing to abandon that arrangement for performance improvements.

In another discussion thread, someone recommended turning off Dark Mode — and that also helped the WindowServer process from running away. Now that I've deactivated separate Spaces for displays, I've reactivated Dark Mode and WindowServer is stable as well. In other words, while I have no idea what's going on, if others are experiencing this issue they can try an either/or approach.

Reply