Tests show how the M3 MacBook Air’s best feature can hinder performance

Macworld

One of the major differences between the MacBook Air and the MacBook Pro is that the Air lacks cooling fans. That means the Air will slow down its performance if the task at hand causes the computer to generate excessive heat. That’s always been the case with the Airs, but apparently, it’s jumped to a new extreme with the M3 MacBook Air.

Max Tech has done some extensive benchmarking with the M3 MacBook Air and discovered that when using the M3 Air in clamshell mode with two external displays, one of the laptop’s major new features, the laptop throttles so much that performance could be cut in half. Max Tech was able to do this by running the 3D Mark Wildlife Extreme benchmark for 20 minutes. After the sixth minute, the performance starts to dip and it continues to do so until about 50 percent of the performance is lost.

We’ve mentioned (and experienced) the MacBook Air throttling with past models, and even saw some of it while testing the new M3 MacBook Air with the laptop open. The clamshell mode (where the Air is closed while connected to external displays) shows a more drastic drop than we’ve seen with past Air models due to the laptop’s lack of a fan.

The argument can be made that the situation that causes the drop is an outlier, but it’s not–3DMark Wild Life Extreme is a 3D graphics test that performs tasks commonly used in high-end games, and Apple touts the Air as a capable gaming laptop. Also, the throttling isn’t just with this one benchmark test. Max Tech saw a similar drop in Cinebench 2024 and with an Adobe Lightroom Classic image import.

How to maintain M3 MacBook Air performance in clamshell mode

Max Tech tried a few different things to prevent the M3 MacBook Air from throttling down. First, they used a Svalt Cooling Block, which is a laptop stand that also doubles as a heat sink, drawing away heat that’s dissipating through the bottom of the case. Then they used the Svalt Cooling Block with a Svalt Cooling Fan Fx. Both methods reduced the amount of throttling, with the Block/Fan setup being better than with just the Block.

Lastly, they cracked the Air case, installed thermal pads, and placed the Air on the Block with a Fan. This setup was the most successful, showing little to no throttling or performance loss. In fact, in some tests, the Air slightly outperformed the M3 MacBook Pro.

Using the Svalt Cooling Block with the Cooling Fan Fx is a simple method to address the problem, but it’s a pricey one–the Block is $279 and the Fan is $49. Add that to the price of the $1,699 15-inch MacBook Air used in Max tech’s testing, and you’re paying $2,023, which is $24 more than the $1,999 14-inch M3 MacBook Pro that will soon be updated to support two displays in clamshell mode like the Air. Cheaper stands with cooling fans are available, but it’s not known how effective they are for this purpose. Adding thermal pads is also relatively easy, but not everyone feels comfortable with cracking open a MacBook to access the inner workings.

Why does the MacBook Air have no fans? So Apple can make it as thin and light as possible. However, the technology does exist where Apple could put fans in the Air without making the laptop bigger. A few months ago, I saw a demonstration of a hacked MacBook Air outfitted with Frore’s AirJet, which is what Frore calls a “solid-state active cooling chip.” They’re fans that are a little bigger than the size of an SD Card. The AirJet drew the heat away from the Air’s CPU, which allowed it to maintain performance. AirJet isn’t a product consumers can buy, but it could be an option down the line as processors get more powerful and basic needs get more demanding.

Apple has not commented on Max Tech findings, but Apple has always positioned the MacBook Air as a general consumer laptop that can do the occasional heavy-duty task usually done with a pro-level app. If you find yourself doing load-heavy work consistently, a MacBook Pro (which has cooling fans) is more appropriate.

While the ability to run two monitors with the lid closed is a new feature, some workarounds let you use two monitors with the display open, For more about the MacBook Air, check out our M3 MacBook Air superguide.