Apple computers are great for all sorts of media applications, and most of the time they work perfectly. Sometimes, however, problems crop up. One of the most common ones you might encounter with your media-making mac is overheating. Luckily, this problem is usually easy to fix!
Overheating has variety of symptoms. The most obvious signs are that the Mac’s aluminum body is hot to the touch, and the fans are noisily spinning as fast as they can. In extreme cases, the mac might even shut down midway through heavy workloads.
Before running out to return your Mac, there are some simple fixes to try. Let’s have a look at them.
MacBook or Mac?
After a few months of use, it’s pretty normal for a MacBook to gather some dust. This is just the result of being thrown in rucksacks, used in dusty libraries, taken outdoors, and, if you’re anything like me, generally just worked with in places no one sane would take their computer. When you put the Mac under a heavy processing load, say editing video, exporting RAW images, or rendering a complex animation, the dust can prevent it from properly cooling down.
On the other hand, if your iMac, Mac Mini or Mac Pro is overheating something major may be wrong. Although they’ll also gather some dust (more if you have furry pets), it should be no where near as much as a MacBook. They’ve got better ventilation and aren’t taken out to weird locations. An iMac, even under heavy load, shouldn’t be overheating at all.
With that said, whether you’re using a MacBook or a Mac, the tips in this tutorial will help you address some common causes of overheating.
Check the Surface It’s Resting On
The first thing to check is the surface the Mac is resting on. On any recent MacBook, the air vents are beneath the screen hinge and along the underside of the edges. If the Mac is resting on a soft surface—like the duvet in your bed—it can block cool air from entering and hot air from leaving. If you put the Mac under a heavy workload, it could start overheating. Don’t edit video in bed!
Instead, if you’re doing processor intensive tasks on your MacBook, make sure it is resting on a hard surface like a desk with plenty of room between the screen and anything behind it. This give the MacBook’s air vents plenty of room to play.
The work surface also matters for Macs, though in a different way. Dust gathers low to the ground and in corners. Underneath a desk is basically the worst place you can put a computer. There’s no room for the fans to work, and when they do, they’re just sucking in all the dust that’s there.
Ideally, you want to place a Mac on a firm desk with plenty of airspace. This isn’t much of an issue for iMacs because the computer is integrated with the screen, but it’s important for Mac Pros and Mac Minis.
Kill Unnecessary or Runaway Background Processes
When you’re using a Mac, there’s a lot going on in the background. Updates might be downloading, photo libraries syncing, backups running, and so on. Most of the time this isn’t an issue because Macs have plenty of processing power to spare. If, however, you need every last CPU cycle you can get, it’s time to kill some unnecessary background processes. Having too much going on could be responsible for your Mac overheating.
The other way background processes might affect your Mac is if they crash. A crashed background process can cause runaway CPU use. When you kill it, your Mac should go back to normal.
To check what’s going on in the background, open Activity Monitor. You can find it in Applications > Utilities.
Click on the CPU tab and then the CPU column to sort all the running processes by CPU usage. If any are using a crazy amount, say 120%, and it’s not Lightroom or Premiere, then a process has probably crashed.
Unwanted background processes won’t be as over the top; they’ll probably take up between 10% and 30% of CPU power.
Regardless of why you need to kill a background process, the method is the same. Select the process and click the black X button in the top left corner. A confirmation dialogue box will pop up so click Quit—or, if the process has crashed, Force Quit—to kill it.
Clean Out the Air Vents
With the two simplest fixes out of the way, it’s time to address the issue of dust clogging the fans. You’ll need to purchase a can of compressed air. Any hardware or office supply store will sell them.
Start by holding the can of compressed air about six inches (15 cm) from the Mac’s vents and gently start the stream. Pan from left to right, top to bottom and make sure to get both sides of the vent. You should see some dust get blown clear.
If just clearing the dust from the vents doesn’t work, you will need to open the Mac and clean the internal fans with compressed air. This is a bit more involved, and only really possible with MacBooks.
If you feel confident enough to do it, get a pentalobe P5 screwdriver (included in most computer repair kits) and remove the bottom plate from your MacBook. Be careful to note where each screw goes. Gently use the can of compressed air to clear dust from the fans and vents. Hold the fans still when you’re blowing on them so they don’t rotate too quickly. Reattach the bottom plate to finish.
If dust was the issue, it should now be fixed.
Take Control of the Fans
One of the best ways to stop a Mac from overheating is to start cooling more, earlier. Macs only spin their fans quickly when they’re under a heavy load so as to run as quietly as possible. If you’re not concerned about noise, you can use fans more actively to keep the whole computer operating at a lower temperature.
By default, there’s no way to control a Mac’s fans so you need to use a third-party app like Macs Fan Control.
With Macs Fan Control you can see the temperature of all the major components. You can use this to create a custom profile for when the fans speed up. You can also just set a constant value.
To take control of the fans, open Macs Fan Control and click on the Custom button for the fan you want to manage. Either enter a custom value or select Sensor-based Value. You can then select the component you want to use to determine fan speed. I’d recommend one of the CPU or GPU options.
By ramping up fan speed earlier, all the components in the Mac will be kept cooler. This should hopefully prevent them from ever getting hot enough to overheat.
Take it to the Professionals
If all else fails, it’s time to take the Mac to the professionals.
Apple has generally reliable customer service. If you’re not able to prevent your Mac from overheating with the tips in this article, bring it to them and they’ll be able to provide a better diagnosis and potentially fix it.