I have been using my Mac for for many months without any problem. But recently all of a sudden the Mac became insanely slow.

I opened Activity Manager to see what was happening. For three processes SystemUIServer, UserEventAgent and loginwindow, the memory gradually increases and reaches upto 2 GB for each process. This completely hangs up my Mac.

I tried the following:

  1. Restart Mac
  2. Restart Mac in safe mode
  3. Manually kill the processes
  4. Remove Date and Time from Menu bar (this was supposed to be the problem for the SysteUIServer process's memory according to many users)
  5. Removed the externally connected keyboard and mouse(some had suggested this for UserEventAgent's memory)

No luck with any of those. The moment I log in, the memory spikes up.

Any idea what the hell is happening? Please help.

  • Seems like it should be possible to track the memory allocations if you see this immediately after boot. I would pick once process and run sudo sysdiagnose SystemUIServer; sleep 600; sudo sysdiagnose SystemUIServer so that you could compare the two snapshots and diff the memory allocation files and decide to investigate yourself, get assistance or report a bug to Apple.
    – bmike
    Commented Oct 19, 2013 at 16:01
  • As a troubleshooting step, you could try reinstalling OS X from the recovery partition (which downloads and installs a new copy of OS X but keeps user files and settings in place) or upgrading to 10.9 once it comes out.
    – Lri
    Commented Oct 19, 2013 at 23:35
  • Can you try running "Repair Disk Permissions" from Disk Utility and see if that helps.
    – VDR
    Commented Oct 21, 2013 at 11:54
  • Maybe you should try to reinstall your system?
    – k1r8r0wn
    Commented Dec 26, 2014 at 4:49

2 Answers 2


First of all: High Memory-Usage is not a bad thing in itself - the goal is to have a performant system and it can accomplish that by using RAM.

That you Mac slows down is more likely a problem that a process or an App is hogging Memory and not correctly releasing it, forcing the system to use Swap-Memory (on your Harddrive) and thereby slowing your system down, but that is just one possible scenario.

I think it is necessary to differentiate that because i think you are looking at the wrong place for your problem.

Other Possibilities could be wrong File Permissions, I/O errors of your Harddrive or SSD, timout issues for some process or App (Google Drive, Dropbox etc), corrupted chaches or swap files.

You should:

  1. check the CPU-Usage in the 'Activity Monitor.app' Is there a Process/App that is using up your CPU and slowing your system?
  2. Check the 'Console.app' in /Applications/Utilities/ for errors and post them here. There might be some clues there, f.e. read/write errors, timeout issues etc.
  3. It is always a good idea use 'Disk Utility.app' in /Applications/Utilities to check your HD/SSD with 'Verify Disk' and after that checking the File-Permissions with 'Verify Disk Permissions'. If you find some errors there you should use the 'Repair' Function.
  4. try booting your system in 'safe mode' by holding the shift key on startup. Can you reproduce the problem in that mode?

Try that and post your findings.


My usage will increase up to over 6GB - that’s right 6GB out of the total 8GB ram installed. This only occurs when certain devices are plugged into the USB at the rear of my Intel iMac. It is only caused by either my iPod or my Fuji digital camera but the Mac immediately slows right down and gives an application error message. Running Activity Monitor and forcing Systemuiserver to quit solves the problem immediately. In normal USB usage i.e. mouse and keyboard there are no problems.

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    Commented Jun 24, 2015 at 12:40

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