Apple engineers reveal how they prevent Mac Pro overheating

How air is made to flow through the new Mac Pro

The new Mac Pro and Pro Display XDR have distinctive Apple designs, but it's not for aesthetic reasons. Both inside and out, the new hardware design on both devices is built to keep the most powerful Mac in existence from overheating.

Speaking to Popular Mechanics, Apple's Chris Ligtenberg and John Ternus revealed some of how their work means the Mac Pro doesn't run too hot, and doesn't have loud fans.

The immediately-recognizable and already copied casing with its myriad holes is key to managing temperature for both the Mac Pro and in particular the Pro Display XDR, which can be used in both portrait and landscape.

"[The pattern] gives us a lot of surface area, which is hugely beneficial," said John Ternus, vice president of Hardware Engineering at Apple. "[For the Display] we wanted free [air] flow through the channels, no matter the orientation."

Part of that solution to dissipate heat regardless of whether the display was in portrait or landscape, was to make the holes hemispherical instead of round.

Ligtenberg, Senior Director of Product Design, explains that previously typical solutions to dissipating heat couldn't cut it.

"It's very easy to get air trapped in channels," he says. "A common solution, passively, is to have a finned enclosure, a heat sink. That was not possible."

Quiet fans

There are fans inside both the Mac Pro and the Pro Display XDR, but with the screen, they are solely to cool certain unspecified components. Ternus and Ligtenberg say that it is the bored metal holes that mean the LED panels can run brightly without problems.

They also say that the design of the holes means the Mac Pro itself gets "about 20 percent more airflow" than previous models.

However, the fans are not incidental. To help with the heat and to keep the Mac Pro quiet — or just apparently quiet — meant Apple had to design the fan blades especially.

"Years ago, we started redistributing the blades," says Ligtenberg. "They're still dynamically balanced, but they're actually randomized in terms of their BPF [blade pass frequency]. So you don't get huge harmonics that tend to be super annoying."

Reports so far say that the Mac Pro is exceptionally quiet. Beyond just quiet, Ternus says a big focus of the team was to make what noise it produces be simply less annoying.

"You can have something at a certain SPL [sound pressure level] that sounds really good," Ternus told Popular Mechanics, "But you can have something that's actually at a lower SPL that grates on your nerves and sounds really awful."

"We want to get really great performance where, you either can't hear it, or if you can hear it, it's kind of a pleasant noise," he continues. "A ton of analysis goes into figuring out how to optimize for that."

Apple's new Mac Pro is now available for pre-order, as is the Pro Display XDR.