WindowServer High CPU

Discussion in 'OS X Yosemite (10.10)' started by bluearctop, Oct 17, 2014.

  1. bluearctop, Oct 17, 2014
    Last edited: Oct 17, 2014

    bluearctop macrumors newbie

    Jul 15, 2011
    After upgrading to Yosemite, I'm seeing very high CPU usage from WindowServer (typically over 50%). On a 2010 MB Pro 2.66/8GB RAM/SSD. Load was under 1.5 typically on Mavericks - now it runs hot and sluggish. Killed off all apps that I thought could be related - no real change.
    I am running an external 2nd monitor, if that matters.

    Anyone else have this problem?

    ** Update , it seems having a second display is causing this. When I unplug the 2nd display, the problem seems to go away (may be too early to tell). I'm using an Accell DisplayPort adapter which has always treated me well.
  2. bluearctop thread starter macrumors newbie

    Jul 15, 2011
  3. PaTor macrumors newbie

    Oct 20, 2014
    second display is a likely culprit

    I had the same issue. CPU starting at 20% and steadily increasing up to 80-90% with peeks of 120%. I was thinking of uninstalling Yosemite (and even Mavericks!) and revert back to Mountain Lion, which seemed to be way more responsive. That is, until I unplugged my external display. Now WindowServer seems to be mostly between 6% and 10% and my Early 2009 iMac 8GB RAM with Yosemite works like a charm. But I cannot use my external display.
  4. bluearctop thread starter macrumors newbie

    Jul 15, 2011
    Right, the problem goes away if I unplug the external monitor - but I need it. I wonder if it could be due to the adapter? What were you using? I'm using:

    Accell B087B-003J UltraAV miniDisplayPort/DVI-D Dual-Link Adapter

    Really hoping I can figure a way to stick w/ Yosemite. Had no issues w/ Mavericks.
  5. PaTor macrumors newbie

    Oct 20, 2014
    Actually you may be right.

    I was using the A1305 Mini DisplayPort to DVI Adapter:

    I am now trying with the A1307 Mini DisplayPort to VGA adapter:

    (my external display supports both)

    So far it seems that VGA is causing less problems compare to DVI. I hope it stays like that!
  6. bluearctop thread starter macrumors newbie

    Jul 15, 2011
    Actually, the same issue exists on my imac, which is using a different adapter. This is a really sucky problem - I am going to need to revert back to Mavericks I think.
  7. Razer(x) macrumors regular


    May 7, 2014
    Same issue on my macbook pro, that's the major difference i'm noticing between mavericks and yosemite
  8. chabig macrumors 601

    Sep 6, 2002
    External video solutions like yours are dependent upon third-party drivers to work. Hopefully yours will be updated by the vendor. You should go to Accell's website and see what they say.
  9. bluearctop thread starter macrumors newbie

    Jul 15, 2011
  10. lklepner macrumors newbie

    Oct 20, 2014
    I'm having the same problem with high CPU usage when my second monitor is attached. I'm using Apple's official display port to DVI adapter.
  11. Horizon Man macrumors newbie

    Oct 20, 2014
    I'm on fully spec'd late 2103 iMac, with a secondary monitor and had absolutely horrible performance when updating to Yosemite, nearly everything was very very slow. I has no choice but to go back to Mavericks.

    The odd thing for me was I checked Activity Monitor and nothing was being maxed out.

    Well I hope that this was the cause of the problem and Apple sorts it out. Otherwise no Yosemite here.
  12. awhellno macrumors newbie

    Apr 30, 2012
    Same issue here on both a 2009 MBP and 2013 rMBP. Clean Yosemite installs. The minute I unplug the external monitor, the choppiness and high WindowServer CPU usage disappears. Looking at performances after several hours of usage, windowserver has used way more CPU Time than any other program or process. There's definitely an issue there.
  13. theSeb macrumors 604


    Aug 10, 2010
    Poole, England
    Oh oh. We have a time traveller over here!
  14. PaTor, Oct 21, 2014
    Last edited: Oct 29, 2014

    PaTor macrumors newbie

    Oct 20, 2014
    External display's high refresh rate may be the problem?

    I have good news.

    Premise: my external display can work at 60Hz or 75Hz. With Yosemite Beta, I had a problem with the screen savers. I solved that problem by increasing the display's refresh rate, from 60Hz to 75Hz. Then I forgot about that - didn't think it would cause any issues. Now my computer is running Yosemite, no Beta.

    And this is the good news: Decreasing the external display's refresh rate to 60 Hz seems to solve the problem (I'm using HDMI connection again now, so no issue there!). I seem to have no problem with the screen savers, and WindowServer CPU usage and system performance seem to be back to normal.

    ***UPDATE EDIT*** After some time the problem is back. Even with 60 Hz. The only working solution so far is to physically unplug the external display :(
  15. bluearctop thread starter macrumors newbie

    Jul 15, 2011
    No such luck here, mine is fixed at 60Hz. I already downgraded one of mine to Mavericks, problem solved. Holding out that we get a fix soon for this though.
  16. peabo macrumors regular

    Feb 14, 2008
    Same problem here on a 2013 Mac Pro.

    I noticed that disabling Little Snitch dropped Window Server usage quite a bit, but the UI lag is still there.
  17. bluearctop thread starter macrumors newbie

    Jul 15, 2011
    I used little snitch too. I have already reverted to Mavericks, so can't test what it's like on this end disabling it.
  18. frank4, Oct 28, 2014
    Last edited: Oct 28, 2014

    frank4 macrumors regular


    Oct 17, 2011
    I have been having a similar recent problem with WindowServer high CPU, causing sluggish response of my 2011 Mac Mini when I'm using the desktop to move some files around. Running dual displays here.

    It seems to be an issue with window transparency first noticed during the beta test program, according to some other discussions. I checkmarked the "Reduce transparency" box in System Preferences / Accessibility and it makes the problem go away. Hopefully Apple will fix it soon.

    ***UPDATE EDIT*** After a half hour the problem is back. Time for a reboot.
  19. bluearctop thread starter macrumors newbie

    Jul 15, 2011
    window transparency did NOT fix it for me. For now, I'm back to Mavericks until this is fixed. Please do submit a bug report w/ Apple.
  20. Jaster macrumors newbie

    Apr 15, 2008
    I don't know about the CPU usage but after my system idles for 5 minutes or so, I go to do something and everything but my mouse cursor is frozen. After about 20 seconds the UI starts responding again. The culprit is definitely WindowServer as my console log is flooded with WindowServer messages. At first I thought it was Firefox due to the highlighted message in the log but that was quickly ruled out.

    Kind of sucks when I'm watching a video and the screen just freezes. Really makes me want to go back to Mavericks despite how nice Yosemite is.

  21. kevinneal macrumors newbie

    Jul 24, 2011
    I'm having the exact same issue of the whole system hanging for 5 minutes including the clock stopping.. I also have high cpu for window server .. the one thing that is really baffling is that this is happening on our 3 Mac Pro's at exactly the same time!
  22. lun macrumors newbie

    Sep 6, 2014
    Just to add another problem:

    I use a second monitor as well and yesterday my MBA 2012 was starting to crawl. Activity monitor did not show a lot cpu usage.

    But WindowServer had been using 1,8 GB memory - climbing every second. Watched until it hit 2 GB after a couple of minutes - fans spinning loudly.

    Was working in preview at that time.

    Did a restart. After that it was back to 55 MB memory. BTW: I have transparency turned off.
  23. bluearctop thread starter macrumors newbie

    Jul 15, 2011
    If everyone submits bug reports to apple it should help get this fixed.
  24. PaTor macrumors newbie

    Oct 20, 2014

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