zerosleeps

Ooh I uncovered this report on Bugzilla this morning and yeah I reckon there’s something to it. I have many gripes with Firefox at the moment but energy consumption is probably number one.

Here’s my M4’s CPU history as reported by Activity Monitor when watching a full-screen YouTube video in Firefox with ProMotion (Apple’s name for variable refresh rate) enabled:

And here’s the same setup, same video, but with my screen’s refresh rate set to 60Hz:

I’ve owned a couple of M-series MacBooks now and the efficiency cores are magical wizardry that use almost no energy at all. You can pin ‘em all day and your Mac won’t get warm and it will sip electricity. Not so much with the performance cores.