The MacBook Pro Core i9 Cannot Maintain Its Base Clock Speed Under Load

Dave Lee posted a video yesterday, showing a Core i9 mid 2018 MacBook Pro averaging 2.2 GHz under load, during an Adobe Premiere render.

The results show just how badly Premiere is optimized for the Mac — a Gigabyte Aero 15X is over 30 minutes quicker (39:37 vs. 7:18) — which has led AppleInsider’s Mikey Campbell to write the following:

It should be noted that Premiere Pro is not optimized for Mac, as evidenced by the Aero 15X performance. Lee failed to test render speeds with Apple’s Final Cut Pro X, or any other app for that matter.

While thermal throttling is nothing new, especially in portables, Lee’s findings are somewhat questionable in that assumptions are being made based on a single machine’s performance with an unoptimized app. Making blanket statements without thorough testing is reckless at best and disingenuous at worst.

While Lee failed to reach out to Apple for comment, it is highly unlikely that the company would ship a flagship product without first rigorously testing its performance. That goes double for a device like MacBook Pro, considering the company’s renewed vigor to serve the professional market.

It took me about 30 seconds to find the following video which exposes the same issues in the 2017 models. The render was done in Final Cut Pro X this time…

In fact, there are many more videos on the subject, so while it is possible that this is a problem with Dave’s specific machine, I’ll go crazy here and suggest that it’s a design problem, especially since there are many reports that just using an external display is throttling some machines, which has led some users as far as replacing the thermal compound that Apple uses on its CPUs.

I have the same issue on my MacBook Pro Escape (late 2016) when rendering larger projects in Final Cut Pro X (especially in 4K) — it slows down considerably the further the render is along.