Apple Finds 2018 MacBook Pro Throttling Bug, Issues Update

Following a high-profile grilling on YouTube and a rash of complaints on Reddit and other forums, Apple has discovered that the new 2018 MacBook Pros have a performance bug. 

Apple is rolling out a macOS software update today that should address the problem.

The controversy started last week when YouTuber David Lee found that the Core i9 version of the MacBook Pro suffered from throttled performance when rendering 4K video in Adobe Premiere Pro. The theory was that the MacBook Pro’s cooling simply wasn’t sufficient to handle Intel’s powerful chip, but that doesn’t appear to be the case.

Apple has discovered a software bug that is negatively impacting performance under sustained workloads on both the new 15-inch and 13-inch MacBook Pro with Touch Bar, regardless of the CPU.

An Apple spokesperson supplied the following statement:

"Following extensive performance testing under numerous workloads, we've identified that there is a missing digital key in the firmware that impacts the thermal management system and could drive clock speeds down under heavy thermal loads on the new MacBook Pro. A bug fix is included in today's macOS High Sierra 10.13.6 Supplemental Update and is recommended.

We apologize to any customer who has experienced less than optimal performance on their new systems. Customers can expect the new 15-inch MacBook Pro to be up to 70% faster, and the 13-inch MacBook Pro with Touch Bar to be up to 2X faster, as shown in the performance results on our website.”

Apple says that once you apply the update being issued today, you’ll enjoy up to 35 percent faster performance on the 15-inch MacBook Pro when performing a similar workload to what David Lee attempted. And you’ll see 70 percent faster speeds on the 13-inch MacBook Pro when performing the same task.

MORE: 2018 MacBook Pro Benchmarked: This Is the Fastest SSD Ever

Apple is adding these performance numbers to the MacBook Pro product page on its website in addition to previous test results.

In our review of the new 13-inch MacBook Pro, its SSD performance was off the charts, and its Geekbench 4 score smoked Windows machines like the XPS 13. However, the MacBook Pro’s video transcode time on the HandBrake app was a bit slower than that of Dell’s machine. We expect the MacBook Pro's numbers to improve. It’s also possible the software update could improve the system’s battery life.

We will be retesting the 13-inch MacBook Pro to determine how well Apple’s software update works. And stay tuned for our full review of the 15-inch MacBook Pro later this week.

Mark Spoonauer
Responsible for the editorial vision for, Mark Spoonauer has been Editor in Chief of LAPTOP since 2003 and has covered technology for nearly 15 years. Mark speaks at key tech industry events and makes regular media appearances on CNBC, Fox and CNN. Mark was previously reviews editor at Mobile Computing, and his work has appeared in Wired, Popular Science and Inc.