By Jason Snell

Apple releases software fix for MacBook Pro slowdown

After a week of controversy following the posting of a video that claimed the new 15-inch MacBook Pro could experience massive slowdowns, Apple on Tuesday acknowledged that the slowdowns exist—and that they’re caused by a bug in the thermal management software of all the 2018 MacBook Pro models. That bug has been fixed in a software update that Apple says it’s pushing out to all 2018 MacBook Pro users as of Tuesday morning.

Here’s the official Apple statement, furnished to Six Colors by an Apple spokesperson:

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.

After YouTuber Dave Lee posted his video showing his new Core i9 MacBook Pro slowing to a crawl while exporting video from Adobe Premiere, as well as reports that the processor on the new MacBook Pros was being throttled all the way down to 800MHz, the company launched an investigation (and contacted Lee for more information about his specific project and settings). Apple’s own internal performance testing hadn’t triggered the issue, which turns out to not be app specific—Premiere, you’re out of the penalty box—and tends to affect heavy workloads that take place over an extended period of time.

The good news is, this doesn’t appear to be evidence that Apple’s laptop design is incapable of handling fast chips, but that someone at Apple had a bad day and failed to include a specific digital key that caused a cascade of bad behaviors in some very specific circumstances. (All laptops throttle the performance of processors in order to regulate temperature, of course, but it’s not supposed to happen to anywhere near the extent seen in Lee’s video.)

Tuesday’s Supplemental Update doesn’t seem to have any impact on performance—all of Apple’s previous claims (up to 70 percent of a speed boost on the 15-inch model versus last year’s version, and 2x the performance on the 13-inch compared to last year’s model) are still accurate. When given an opportunity to re-run his tests after applying the fix, Lee should find that his MacBook Pro is now clearly faster than last year’s model.

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