Mark Coppock / Digital Trends
People are getting their hands on the new M4 MacBook Air this week, which means they’re posting lots of discoveries about its performance (and the blueness of the new Sky Blue color). While editing photos in Lightroom Classic, YouTuber Vadim Yuryev noticed that the CPU workload was being handled almost completely by the laptop’s six efficiency cores.
Woah!! Apple’s M4 MacBook Air is pushing this CPU workload to all 6 of the Efficiency cores while the 4 Perfomance cores are barely being used. (Left photo)
Compare that to the M3 (right) where the 4 Perfomance cores are seeing a lot more use.
Photo editing in Lightroom Classic pic.twitter.com/y17D8G0ypB
— Vadim Yuryev (@VadimYuryev) March 13, 2025
Spotted by Wccftech, this behavior is interesting because the image editing software is so CPU-intensive that anyone would assume it needed the performance cores to run. This was certainly the case for the M3 MacBook Air, which Yuryev shows using all four performance and all four efficiency cores to get the work done.
We don’t know why this behavior has changed, how purposeful it is, or if it’s specific to Lightroom Classic — but the benefits could be significant. Keeping the efficiency cores busy and limiting the activity on the performance cores could improve battery life and keep temperatures down.
That said, we don’t know from Yuryev’s post how well the software is running while in this state — we can assume he’s pointing it out because it’s running fine but we don’t know for sure.
It’s also not entirely impossible that this is a bug of some kind — the performance cores are there to be used, after all, or else they’d be pointless. So the sheer amount of activity on the efficiency cores while the performance cores sit almost unused does seem quite odd.
With outlets like Wccftech and tech influencers everywhere experimenting with this new model, we’ll likely find out soon whether this was a fluke or an intended feature of the new MacBook Air.
Willow Roberts has been a Computing Writer at Digital Trends for a year and has been writing for about a decade. She has a…
Tim Cook just teased the M4 MacBook Air, and it’s coming this week
Apple CEO Tim Cook just posted a teaser to X with the caption “This week.” and a six-second video showing the words “There’s something in the AIR.” We’ve been expecting the M4 MacBook Air announcement for a couple of weeks now, and with the iPhone 16e reveal out of the way, it looks like this is the week.
https://x.com/tim_cook/status/1896589954517701057
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A new version of MacBook Air powered by Apple’s M4 processor is right around the corner, it seems, and might be launched within a week. “Apple is preparing to make a Mac-related announcement as early as this coming week,” reports Bloomberg, adding that the reveal is imminent.
The current-gen MacBook Air with M3 silicon was announced in the first week of March in 2024, and it seems Apple is sticking with its refresh schedule rather strictly for its popular entry-level laptop. The machine will likely arrive in 13-inch and 15-inch formats, just like its predecessor.
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It looks like the next-gen MacBook Air laptops with the M4 silicon upgrade are merely a few weeks away. According to Bloomberg, Apple is toning down inventory of the current-gen model and is readying the M4-equipped trim for a launch in March.
Apple is unlikely to make any design changes, serving the same aesthetic formula it introduced with the M2 MacBook Air. The most notable change, of course, is going to be the M4 silicon, which enhances the processing chops and lifts the efficiency figures, as well.