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iMac Running Slow? Here’s Your Checklist to Fix It!
Editors note: this post was originally published in August 2015 and was updated in 2017 to reflect new reviews and experiences.
Look no further if you’re living through the frustrating experience of operating an iMac running slow— we’ve got you covered!
1. Check your free disk space
Your issues might come in part from a full hard drive—and you encounter a lot of issues with an iMac when your hard drive space gets low.
- Open Apple icon
- Select About this Mac
- Select Storage
If you’re running low on storage, we recommend downloading CleanMyMac 3 from MacPaw.
2. Invest in RAM
Another easy way to increase your iMac’s speed is to upgrade your RAM. RAM, or random access memory, provides “space” for your programs to operate. Your computer stores instructions and data in RAM while powered on— and deletes everything stored in RAM once you turn off the computer. Learn more about RAM with our article on Mac RAM and storage.
3. Edit your start up items
Your computer starts up certain apps every time you launch. You want this list to be as small as possible. The less work your computer has to do when it starts up, the faster it launches.
- Apple Menu
- Then System Preferences
- Then Login Items
4. Carry out soft resets (SMC & PRAM)
Try carrying out a couple of soft resets: the SMC (System Management Controller) reset and the PRAM reset. These should help speed up your computer.
The SMC in your iMac is a very important controller. It manages functions such as thermal monitoring, power button response, startup of hard drive spin down cycles, and returning to sleep mode. Your SMC getting out of sync can make your iMac slow, leading to several performance issues.
Thankfully, the reset is pretty quick and easy!
- Shut down your iMac
- Unplug the power cord from the wall outlet
- Press and hold your iMac’s power button for 15 seconds
- Release the power button
- Reconnect your iMac’s power cord to the wall outlet
- Wait for 5 seconds
- Turn on your iMac
Though a very simple procedure, the SMC reset can do wonders to a slow iMac, even bringing it back to speeds that you only enjoyed when your iMac was brand new.
PRAM is short for Parameter RAM. This little memory module also, like the SMC, controls a many functions (like startup volume monitoring, speaker volume control, display resolution control, and the all-important tracking of date and time).
Resetting your iMac’s PRAM is another very easy procedure
- Shut down your iMac
- Power your iMac back on
- Immediately press the following combination of keys, before you see the grey startup screen: Command + Option + P + R
- Press and hold until your iMac restarts
- Allow your iMac to startup like normal
Please note that you might have to reset your date and timezone data after a PRAM reset. This is perfectly normal and nothing to be alarmed about. All your data and other settings are still intact.
These two resets can be great to fix your issues with a slow iMac, particularly if the performance issues came out of nowhere, without any rational explanation.