What To Do When Your Mac Freezes And Runs Slow


We’ve all been there. Sometimes you’re using your Mac quite happily and suddenly things come grinding to a halt as an errant application begins to suck up resources and hangs or freezes your activities. Typically, you’ll notice things start to slow down, the hard drive might become noisy, and you’ll keep seeing the “spinning wait cursor” (its official name, but commonly known as the “beach ball” or “wheel of death” - pictured above.)

First, Why Does Your Mac Hang and Slow Down Anyway?

The most common reasons for your Mac freezing / hanging and slowing down are:

  • An application has a bug that is causing it to consume too many resources
  • An application is legitimately resource intensive and your computer is slow
  • Your Mac has too little memory for your demands
  • Too many applications are running at the same time
  • You have multiple applications all trying to use the disk at the same time

If you have a reasonably modern Mac and you have less than a handful of applications open, it’s unlikely your problem is due to lack of resources, since modern Macs come with quite a lot of memory and incredibly powerful CPUs. If you have more than 1 gigabyte of memory and any dual-core processor, and you’re not trying to render movies at the same time as ripping DVDs and downloading from the Internet, resource demands are unlikely to be your problem. If shutting down applications and doing less things at a time does solve your problem, then your computer is likely to need an upgrade of some sort.

Instead, and this is quite common, you probably have an application that has encountered a bug or has otherwise “run away with itself” and which needs to be shut down. Applications are not perfect and there are many cases where they can become errant and require manual shutdown. How you shut down errant applications depends on how slow your computer is running.

Activity Monitor: The Best Option If You Can Just About Use The Machine

If your machine is semi-responsive and you’re able to click on menus and have them appear within a few seconds, the best option is to run Apple’s own “Activity Monitor” to find out what application is causing you problems. You can launch Activity Monitor following the instructions in our “How to Launch Any Program Quickly” article, or by navigating through your hard drive to “Applications” then to “Utilities” and then double click on “Activity Monitor” (seen below):


Once Activity Monitor is running, it looks like this:


Activity Monitor is designed to show you what resources running applications are using. It shows the processor usage under the “CPU” column, the application name under “Process Name” and the amount of memory used under the “RSIZE” column. You can click on the column headers to sort the columns by their values, so it’s easy to find out which application is using the most CPU or memory (the two biggest culprits for a slow Mac.) Just click on the CPU heading until the higher numbers at the top, and you can see what process is running amok!

Tip: If Activity Monitor loads but does not display a window like the above, try pressing Cmd+1 on your keyboard to bring up the window shown in the screenshot.

To kill a process, just click on its row in the Activity Monitor, then click the “Quit Process” icon at the far top left. You may need to do this a few times if the application fails to quit. If all goes well, your Mac should become more responsive (unless you have more applications you need to quit - just keep an eye on the numbers!)

Force Quit: For When Things Get REALLY Slow

If your machine is not responsive enough to run Activity Monitor, yet your machine is not 100% “locked up” then Force Quit is the best port of call. Force Quit is a simple menu provided by OS X that lets you shut down applications with a single click. To bring up Force Quit just press Cmd + Alt + Escape (a.k.a. Cmd + Option + Escape) on your keyboard where Cmd + Alt are next to your space bar, and Escape (written as “Esc” on most keyboards) is at the top left. When pressed, Force Quit should appear reasonably quickly:


Force Quit does not show all of the various processes running on your machine but just shows the main applications. To “kill” one, just click on its name and then click “Force Quit.” You can repeat this over and over if it does not work the first time, and you can also work your way through all of the applications if you are not sure which one is causing the trouble. If you do kill all your applications, however, it is a good idea to restart your machine afterwards in order to get a clean start.

Power Down: The Last Resort

If your machine is so unresponsive that Force Quit doesn’t even come up, you may need to power down your machine mid-flow. This is not a desirable course of action but may be all you can do.

WARNING: Powering down a machine without going through a true shutdown or restart process has the potential to cause problems, particularly if the hard drive is in heavy use, as data may only get half-written to disk. MacYay takes no responsibility for anything that occurs if you power down your machine in this way. That said, in the several times I’ve done this in the last few years, no bad effects have occurred, as computers nowadays are a lot more resilient to this sort of activity than they were in the past!

To power down your machine, the best option is to HOLD DOWN the power (on/off) button for several seconds. Do not just pull the mains cable / cord out of your Mac! Instead, just hold down the button you use to ordinarily turn on the machine from a cold start. Once the screen goes black and the machine is quiet, your machine is off. Wait several seconds before restarting your machine.

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Comments (3)

Another thing I do to Force Quit applications, if your computer is still somewhat responsive, is right-click on the application in your dock and select “Force Quit”.

Nate Leavitt — June 19th, 2008

I use Activity Monitor more than just about any other app or even any other util I’ve got.
Tells me what’s goin’ on under the hood.
And which app just MIGHT need to get dumped & restarted to free up some RAM. Or dumped altogether. Like modem-on-hold. itunes helper. don’t need ‘em…..
And most useful, which background things are sucking up the most RAM juice…. and which can be dispensed with considering their RAM use vs. their real usefulness, specially when I’ve got lotsa windows open & so there’s lotsa mem address shuffling/open space finding going on by OSX.

Kevin — December 7th, 2008

what do i do after i have push the on/off button and it wont start back up again?

ek — December 27th, 2008

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