After rumors of a new performance-boosting “Pro mode” in the latest macOS Catalina beta made headlines on Wednesday, developer Marco Arment is arguing that Apple should bring an iPhone-style Low Power Mode to the MacBook.
As noted by MacRumors, since the release of iOS 9, a Low Power Mode has been available on the iPhone that reduces the amount of power the device uses when the battery get low.
Arment says he currently uses a third-party app called Turbo Boost Switcher Pro that allows users to disable Intel Turbo Boost on their Mac’s processor. Arment says disabling Turbo Boost on his 16-inch MacBook Pro has increased the laptop’s battery life by an estimated 30-50%. He also says its a “much better laptop” the vast majority of the time he uses it.
With Turbo Boost disabled, peak CPU power consumption drops by 62%, with a correspondingly huge reduction in temperature. This has two massive benefits:
- The fans never audibly spin up. When Turbo Boost is enabled, the fans annoyingly spin up every time the system is under a heavy sustained load. Disable it, and it’s almost impossible to get them to be audible.
- It runs significantly cooler. Turbo Boost lets laptops get too hot to comfortably hold in your lap, and so much heat radiates out that it can make hands sweaty. Disable it, and the laptop only gets moderately warm, not hot, and hands stay comfortably dry.
Arment admits that the savings come at a cost to performance, but:
- It’s not noticeable on most workloads.
- Parallel workloads are affected far less than single-threaded tasks, and most modern heavy workloads are parallelized.
- This is an 8-core laptop that’s competitive with my iMac Pro! It’s much faster than most people need (myself included) most of the time, so I can spare some performance to get other benefits.A fast laptop isn’t very useful if your hands are too sweaty to type, the battery dies in the middle of a flight, or the loud fans ruin your audio recording.
- When I really want to maximize performance, Turbo Boost Switcher Pro lets me quickly toggle it in the menu bar, so switching between modes is easy.
Arment worries that since Turbo Boost Switcher Pro relies on a legacy kernel extension that it likely won’t be supported in future versions of macOS. He ends his blog post with a plea to Apple to offer an official Low Power Mode for macOS that disables Turbo Boost.
“Please, Apple, make this feature official: give us a Low Power Mode for macOS that disables Turbo Boost to keep our laptops cool, quiet, and long-lasting at times when those are more important to us than speed.”