Apple Releases New 2018 MacBook Pro Update, Fixing CPU Throttling/Thermal Management Bug

Today Apple is sending out an update to all it’s new MacBook Pros released earlier this month which will address a bug resulting in performance issues in relation to the MacBook Pro’s thermal management system under certain conditions. To specify, the bug affects the new  MacBook Pro’s thermal management system and makes it force clock speeds lower than necessary when performing heavy tasks.

Apple have provided 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 apologise to any customer who has experienced less than optimal performance on their new systems.

Today’s update follows several reports which appeared to be performance issues related to CPU throttling. 9to5mac’s tests before the update show that throttling with the 6-core Core i9 in the new high-end MacBook Pro can be fairly aggressive with Final Cut Pro X exports, but the bug discovered by Apple is not app specific and affects only intense workloads in some cases.”

While the majority of reports revolving around the bug specifically refer to the high-end Core i9 machines, 9to5mac have been warned that the bug affects all of the new MacBook Pro models and they advise that all users should install today’s High Sierra 10.13.6 Supplement Update just to be safe.

We believe that the reason Apple didn’t pick up on the issue before it got out was because their own internal benchmark testing wasn’t affected by the bug, which means that their claims that 15″ MacBook Pro is 70% faster and the 13″ MacBook Pro with Touchbar to be twice as fast still remain true after the update is installed. 

After installing the update themselves, Apple internally tested similar workloads such as Premiere Pro (which was part of one of the reports) and found that they were unaffected, which means that the update is sufficient and does indeed fix the bug causing this thermal management issue. 

Overall, we highly recommend that any and all MacBook Pro users install today’s Supplement Update so they can avoid any issues possibly caused by this bug.