MacBook Pro (mid 2018) throttling

As expected, the #ThrottleGate controversy is being looked into by anyone who has their hands on the new MacBook Pros.

John Poole on Geekbench’s blog, running a CPU-only test:

Why does this test not replicate the throttling seen in other tests? Part of the issue is the test themselves. Premiere uses both the CPU and the GPU, while Geekbench only uses the CPU.

The i7 ran at an average 3.0-3.1 GHz, which is above the CPUs base 2.6 GHz frequency, but below the advertised 4.0 GHz Turbo Boost for 6 cores. So is it throttling or is the test just not maximizing load on the CPU?

Jeff Benjamin, for 9to5Mac, ran a test based on Final Cut Pro X:

Leaving the Core-i9 configured as default, I exported the video in 5 minutes and 30 seconds. Throttling was definitely noticeable during the export, as you can see from the following chart created from Intel Power Gadget log data.

Curiously, when he set the CPU to utilize only four cores, it was faster than when using all six.

Mike Wuerthele, for AppleInsider, opted for Cinebench 15:

We shifted to a different benchmark for our own series of tests. Using Cinebench 15, we ran 10 total runs on the i9 MacBook Pro.

Immediately after starting the first test, the CPU clock speed shot up to 4.17 GHz. It rapidly drops to 3.86GHz until it hits the chip critical temperature of 100C. It then drops nearly immediately to 2.57GHz and also nearly immediately drops to 84C.

The speed of the processor varied between 2.33GHz and 2.9GHz generally, with one profound dip to 2.02GHz, and then the range drops to a peak of 2.65Ghz.

I think it’s same to assume that all MacBook Pros will throttle under load, especially when both the CPU and GPU are being taxed. A potential solution for this problem is running an eGPU, which should help (in addition to being significantly faster than the one on-board). Surprisingly, an iMac Pro may not solve everyone’s problems when it comes to video editing — it was a slower in 9to5Mac’s test than the MacBook Pro:

Xeon CPUs lack onboard hardware video encoding, dubbed Intel Quick Sync Video. So even though the iMac Pro runs circles around the MacBook Pro from a thermal perspective, it doesn’t really matter in this test.