The new high-end MacBook Pro and “thermal throttling”

A new video is making its way around the net, under the title “MacBook Pro 15 (2018) – Beware the Core i9”. The video (embedded below), is a reasonably measured analysis of one specific new MacBook Pro model, the highest end, spec’ed with a 2.9GHz 6-core Intel Core i9 processor.

Before we get into the video at all, the issues Dave Lee raises are specific to this configuration. I’ve seen not seen anything to make me believe the over-throttling Dave encountered occurs on lower-spec’ed models. Per usual, ping me if I’ve missed anything, or if you see someone encountering this issue with, say, a 2.6GHz 6-core i7.

On to specifics:

Dave runs an Adobe Premiere render on Mac and Windows, the Mac using the i9, and the Windows machine using an i7. Under high load:

  • The Windows laptop (Intel i7) runs at an average clock speed of about 3.1GHz, temp of ~87°C
  • The MacBook Pro (high end i9) runs at an average clock speed of 2.2GHz, temp of ~90°C

In this specific case, with this specific configuration, with this specific i9 chip, the MacBook Pro runs hotter and slower under intense load.

Dave then sticks his MacBook Pro in the freezer and repeats the experiment, and the thermal throttling is significantly reduced, as the Mac no longer has to throttle performance to keep the machine from overheating.

I’d be very interested in seeing this experiment repeated by other folks. Thermal throttling is not the villain here. It’s about the ability of the Mac itself to dissipate heat efficiently. Once the chip heats up, that’s when thermal throttling kicks in.

Watch the video, draw your own conclusions.