XCode Simulator running slow

Discussion in 'iOS Programming' started by lastcall, Dec 23, 2013.

  1. lastcall macrumors member


    Jan 10, 2013
    I'm running XCode 5 with the latest Mavericks 10.9.1 update, and whenever I use the iOS 6.0/6.1 simulator,
    my app runs extremely slow with choppy graphics.

    I found this command after searching on the subject:
    > sudo sysctl -w kern.timer.coalescing_enabled=0

    But I have absolutely no idea what it does or what effects it has on my computer.
    I don't understand why I even need to do it at all.
  2. DannyBres macrumors 65816


    Oct 30, 2007
    Is the app doing something stupid that is CPU/GPU intensive?
  3. Duncan C macrumors 6502a

    Duncan C

    Jan 21, 2008
    Northern Virginia
    I remember reading about that, but don't recall the specifics. It is legit anyway. It's not like somebody's trying to get you to type "sudo rm -rf /" or something.

    I'd suggest googling it.

    Are you doing a lot of logging (using printf, NSLog, or debugger breakpoints with logging)? Those really slow down your code a lot.
  4. lastcall thread starter macrumors member


    Jan 10, 2013
    This is old app of mine that has ran smoothly in the past, in both release and debug mode. The only thing that has changed is Mavericks.

    If I change to a different simulator other than iOS 6.0/6.1, the problem seems to go away. But, this is very odd behavior. Something that I shouldn't have to fix myself, as it seems to be related to the operating system.
  5. Tander macrumors 6502a


    Oct 21, 2011
    Johannesburg, South Africa
    Which version of Xcode 5 are you running? 5.1?

    If so.. from the release notes:

    Hope this helps.

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