May 31, 2023
The new MacBook Air runs so hot that it affects performance. It isn’t the first time [Updated]
Andrew Cunningham - Jul 22, 2022 8:40 pm UTC Update : Based on the iFixit teardown, a previous version of this article asserted that the M2 MacBook Air didn't include any kind of passive cooling for
Andrew Cunningham - Jul 22, 2022 8:40 pm UTC
Update: Based on the iFixit teardown, a previous version of this article asserted that the M2 MacBook Air didn't include any kind of passive cooling for the M2 chip. Multiple Ars commenters have pointed out that this is likely to be incorrect—thermal paste does appear to bridge the gap between the M2 and the strip of metal above it, and that metal strip is likely to serve as some kind of a heat spreader (in addition to an RF shield that helps avoid wireless interference).
It remains true that the peak temperatures of the M2 chip in both the MacBook Pro and MacBook Air can exceed the peak temperatures of the M1 chip during sustained workloads, including large photo and video export jobs. The M2 Air's thermal throttling can occasionally slow it down enough to make it no faster than the M1 Air it replaces, though this is something many users will never encounter in their day-to-day use.
It also remains true that, by adding more thermal pads to whatever heat spreader Apple has included, the M2 Air's performance can be measurably improved while also dropping its peak operating temperatures. This is something that should be considered when deciding between the Air, the M2 Pro, or the larger MacBook Pros with M1 Pro and M1 Max chips and active cooling systems.
Original story: If you read iFixit's teardowns, in-depth reviews, or follow any tech YouTubers, you may have read that the M2 chip in the newly redesigned MacBook Air has some problems with heat.
While not something every MacBook Air owner will notice, we noted in our MacBook Air review that the M2 in the MacBook Pro could be as much as 30 percent faster than the exact same M2 in the MacBook Air. More adventurous YouTubers have gone further—the Max Tech channel installed thin thermal pads on the MacBook Air's M2 that significantly boosted the chip's performance in both real-world and synthetic benchmark tests, while lowering the chip's maximum temperature from a toasty 108° Celsius to a less-toasty 97° Celsius.
Before we continue, this mod isn't something that we condone. Apart from voiding your new MacBook Air's warranty, adding thermal pads that conduct the M2's heat to the bottom of the laptop could cause all kinds of unintended consequences, including but not limited to "making your lap really hot." You also risk causing accidental damage to the M2 or other components. Seriously, please do not mod your new MacBook Air just because a YouTuber did it (or at least give other people more time to discover all the unintended side effects so that you don't have to).
Thermal pads, heatspreaders, and heatsinks all work the same way: They make close contact with the processor and conduct heat away from it. As that heat is spread over a larger surface area, it becomes easier to dissipate, making it easier to keep the processor cool. The MacBook Airs include passive heatspreaders (that is, one without a fan) that conduct heat away from the chip, while the M1 and M2 MacBook Pros use active cooling systems that pull in cool air and eject hot air for even more effective cooling.
But it does seem like the passive heatspreader in the M2 version of the Air is having a harder time than the one in the M1 version of the Air. Because of the higher temperatures, the M2 needs to slow itself down more aggressively to prevent overheating. Especially for people editing and exporting high-resolution photos and videos, it means that the M2 in the Air can have trouble running faster than the M1 it replaces.
This isn't the first time a MacBook Air has had noticeable thermal throttling issues—the 2020 Intel MacBook Air was also capable of much better performance than it delivered, and the culprit was also the cooling system.
In a real do-as-I-say-and-not-as-I-do situation, I modded my 2020 Intel MacBook Air, so I can speak with more authority on its heat issues. The problem there wasn't that Apple didn't include a heatsink and fan, but that the heatsink was set up poorly—there was too large a gap between the bottom of the heatsink and the top of the processor, and Apple had to use a larger glob of thermal paste to close that gap. But where a thin layer of thermal paste can fill in tiny gaps and improve conductivity and heat transfer, too much thermal paste leads to a much less efficient transfer of heat. Oops! Possible fixes for the issue include using thin copper shims to close the gap between the CPU and the heatsink, as well as placing a thermal pad on top of the Air's heatsink to improve conductivity.
Even though the causes of the thermal problems in these two MacBook Airs are different, both problems certainly feel avoidable. Maybe Apple is trying to save some money, or make the MacBook Air a tiny bit lighter. Maybe the company thinks that the performance degradation won't actually be noticeable by most people most of the time (which is probably true). Maybe the company doesn't think most people will use their MacBook Airs for sustained workloads that make the processor hit its thermal limits (though this would be an odd assumption to make, given the company's renewed interest in gaming in macOS Ventura and the MacBook Air's position as Apple's most popular laptop).
Whatever Apple's reasoning, letting the M2 run at higher temperatures over many years could eventually become a reliability issue—the hotter computer components run, the faster they wear out. This is also the MacBook Air design we'll probably live with for the next three to five years, going by precedent. Apple should be cooling all of these systems properly, for the good of the hardware and the people using it.UpdateOriginal story