418 Teapot

Low Power Mode for Mac laptops: making the case again

Marco Arment:

In light of today’s rumor that a Pro Mode may be coming that seems to offer benefits in the opposite direction,1 I wanted to re-make the case for a Low Power Mode on macOS — and explain why now is the time. Modern hardware constantly pushes thermal and power limits, trying to strike a balance that minimizes noise and heat while maximizing performance and battery life. Software also plays a role, trying to keep everything background-updated, content-indexed, and photo-analyzed so it’s ready for us when we want it, but not so aggressively that we notice any cost to performance or battery life. Apple’s customers don’t usually have control over these balances, and they’re usually fixed at design time with little opportunity to adapt to changing circumstances or customer priorities. The sole exception, Low Power Mode on iOS, seems to be a huge hit: by offering a single toggle that chooses a different balance, people are able to greatly extend their battery life when they know they’ll need it.

Computers today are fast. Heck, even the speaker on my cabinet is super fast. But battery life has always the biggest worry when working ‘on the go’. I remember when I went from my first Windows XP laptop to an intel Macbook and I was amazed by the battery life. I think I got a whopping 3 or 4 hours of watching video and listening to music between charges. That pretty much stayed the same until Intel did some amazing things with power management in 2013 and I think we got Macbook Airs that lasted well over 10 hours.

For the first time I could last a day in the library without having to charge my laptop. Well that is if I was actually doing what I was supposed to be doing and not playing OpenTTD or Minecraft on a group server. After that there doesn’t seem to have been a lot of progress in Battery life. The laptops got faster, but not much faster. I went from a 13” 2015 Macbook pro to a 15” 2017 Macbook pro, and except for Xcode build times there wasn’t much difference in day to day usage.

What I have noticed is that my battery life in practice did get worse though, mostly due to my Mac switching to discrete graphics because I have some utility running in the background, Spotlight indexing or Photos thinking ‘Now’ is a great time to re-analyse every single photo in my 1tb photo library.

Marco mentions some great tips in his post, and disabling Turbo Boost is one that I’ve done in the past when he talked about it on his podcast, and saw really positive results. Introducing a low power mode in macOS would be great, but I think I would be running it in 95% of the time when I’m disconnected from power, and only go full Turbo Boost when I’m connected to power.

Who knows maybe Apple will make Siri so smart that it will sense when you actually need the power or when it’s okay to take 10 seconds longer so you can enjoy a sip of your fine brewed coffee tea.