Apple confirms bug in latest MacBook Pros impacting performance

The details: An issue with the heat management software was causing the machines, under certain workloads, to throttle down the main processor to unacceptably low levels, impacting performance. The software bug can affect all of the new MacBook Pros, not just the ones with the top-of-the-line Intel Core i9 chips as some had speculated.

What they're saying: "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," Apple said in a statement. "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."