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The case for a Low Power Mode on Mac notebooks

macBook (Image credit: iMore)

What you need to know

  • Apple is thought to be adding a Pro Mode to portable Macs.
  • Pro Mode will increase performance but impact battery life.
  • But there's a case for reducing performance to improve battery life instead.

With the news that Apple appears to be working to add a new Pro Mode to portable Macs, it raises an interesting question. Which is most important to users – battery life, or processing power?

As ever the answer isn't a simple one. There will always be power users who want to be able to edit 4K video while sitting at the top of a mountain. But there will also always be people who need their MacBook to last a full day of writing at the coffee shop, too. How do you cater to both? Even more difficult, how do you cater for someone who needs both things in the same notebook but at different times? Options, that's how.

If Apple is indeed going to allow users to toggle a Pro Mode on and off, it's giving them the option of sacrificing battery life to improve performance for a specific task. But why can't we have an option to do the complete opposite? If you want extra battery life but don't need your iPhone to be as snappy, or its screen as bright, Low Power Mode is there for you to use. But it's nowhere to be seen in macOS. Nor iPadOS, for that matter. Which just seems....odd.

It's a tune that developer and podcaster Marco Arment has been singing to for a long time and he shared his thoughts in a recent blog post on the subject. And he also pointed to the lack of options as being a problem on portable Macs.

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.

But again, there's Low Power Mode on iPhone.

Arment has been jerry-rigging Low Power Mode into macOS by using the Turbo Boost Switcher Pro app that temporarily disabled a Mac's CPU from using its Turbo Boost function. That prevents the chip from ramping up the clock cycles to try and get through big workloads as quickly as possible. And as a result, battery life increases. And heat reduces. And fans slow down. get the idea.

Yes, disabling Turbo Boost makes the Mac slower when running intensive, CPU-hungry workflows but if you're more interested in making a battery last all day that's a trade-off you should be able to make for yourself. As Arment says, Apple isn't normally one for giving you those kinds of options. But it does it on iPhone, the one product it tries its damndest to simplify in as many ways as possible. And often to its detriment.

It's likely most people wouldn't even notice their Mac was running in Low Power Mode, anyway. Macs are already way more powerful than the majority of people need them to be. General tasks don't need multi-core processors running anything close to full bore and the fact that so many people get by on the lowly MacBook is a testament to that.

Oliver Haslam

Oliver Haslam has written about Apple and the wider technology business for more than a decade with bylines on How-To Geek, PC Mag, iDownloadBlog, and many more. He has also been published in print for Macworld, including cover stories. At iMore, Oliver is involved in daily news coverage and, not being short of opinions, has been known to 'explain' those thoughts in more detail, too.

Having grown up using PCs and spending far too much money on graphics card and flashy RAM, Oliver switched to the Mac with a G5 iMac and hasn't looked back. Since then he's seen the growth of the smartphone world, backed by iPhone, and new product categories come and go. Current expertise includes iOS, macOS, streaming services, and pretty much anything that has a battery or plugs into a wall. Oliver also covers mobile gaming for iMore, with Apple Arcade a particular focus. He's been gaming since the Atari 2600 days and still struggles to comprehend the fact he can play console quality titles on his pocket computer.

  • "Which is most important to users – battery life, or processing power?" I'm totally fine with you wanting a low power mode, but pitching it as an appeal to the majority of people leaves a bad taste in my mouth. Those of us that need every possible conceivable erg of computing power out of these devices really, really, really need it. It's not zero sum game. Apple makes most of its devices for people that want thin+light and battery life. Both are important, but trying to assert the tyranny of the majority for those who use their Mac for purposes that could be served as well by an iPad or (shudder) a Chromebook, you have a Low Power mode already. Turn the screen brightness down. That's the number one thing using your battery if you're just browsing the web and writing documents in Pages or Office or Google Docs. For those of us waiting most of our workday for that Swift compiler to finish, trying to keep our creative train of thought amidst interruptions, we need every bone Apple can throw us. Please don't undermine that. The solution for people needing longer battery life is simple; turn the screen brightness down a little. Turn off the bluetooth and wifi radios if you're not using them. We (those that need more power) have no solution (except maybe to use a 3rd party utility to turn the fans up, and stick a cooling pad under the Mac, but this is marginal relief at best). Apple has to give us one. As regards the 16 inch Macbook Pro, Apple stuck the biggest battery the FAA will allow in it. This was the right tradeoff. Apple makes the 13 inch Pro, and the Macbook Air for those that want long battery life AND want the lightest, slimmest device possible. I could totally see Apple making a low power mode that shuts off Turbo mode, but're not going to go into Turbo mode if you're using the machine as lightly as you suggest. Suggesting that those of us who need the power will want to wait longer for our tasks to complete to keep the battery going, that's......not realistic. I carry a pair of HyperJuice batteries with my Macbook Pro 16 inch, and if I have to carry a third one to keep it going when in High Power mode, I rejoice. Light and Thin / Battery Life / Power - pick two. I'm not against your Low Power mode as an option for users, but I really take exception to always, always, pitching everything as a 'most users' tyrannical majoritarian kind of slant. Apple has (finally!) thrown Mac pro users a bone or two, albeit those bones are crazy expensive and we had to wait years for them (16 inch macbook pro with 64 Gb RAM, 8 cores, and 8 TB SSD, and the 2019 Mac pro....finally....yes I have BOTH of these). Please don't hate on our very valid needs.
  • I don't really understand your concern. I get that you, and many like you, need the power, and you have it. I don't really imagine you and those like you are the majority though. That would make those that don't need the power that is available, 'most'. For them, us, we don't have the option of choosing to throttle the power to maximize the time. Doing that for us, I imagine the majority, wouldn't hurt you. BTW, on my Windows machine I have a slider that goes from maximize battery life to maximize performance. It sits right in the middle by default.
  • macOS already has a lower power mode, it's automatic and doesn't require the user to do anything, it's the reason you barely hear the fans on their machines when doing light tasks and why they have such great battery life. I never liked the slider on Windows, often you'd find people have it in power-saving mode or with the manufacturers own "power-saving" software which would slow down the whole computer for no reason at all, I've had so many people come to me with "slow" machines that have been set in this mode. What I like about macOS is that it's all happening automatically, there's no annoying configuration, it "just works".
  • I have serious questions about the "Pro Mode" that people keep going on about. Without Pro mode, I know of a couple of applications that can drain a full battery while plugged into the Apple charger and cable in approximately 2 hours on a modern MBP. If the battery and charger TOGETHER can't last more than two hours when the MBP is doing serious computations, what makes anyone believe a "Pro" mode is going to be any different?
    Maybe I am wrong, but I'm guessing that "Pro" mode is just Apple renaming the GPU switching and the ability to force use of the discreet graphics card. These days Apple's marketing game is still going strong, while their hardware game is a very solid
    'meh'. I realize that many of Apple's problems are directly tied to Intel's inability to deliver new CPU's. However as @pfunkster said, they could do MUCH more to improve the thermal efficiency and performance of what is available if they would get off of their stupid 'thinner, lighter, smaller' kick. If the person shopping for a 15" MBP cares about those three things the most, that simply means Apple is missing an opportunity in the 15" standard MB market. But, in catering to that crowd, they are losing the actual pro market. As for the need for 'low power mode' I question whether this is needed. If you want your laptop to last longer, close out all applications you aren't using. As @pfunkster said, turn down the brightness. If you don't need it, disconnect from Wi-Fi. If Apple were to build a 'low power mode' people would immediately disable it once they realized how slow everything ran (because the wouldn't follow those previous simple directions.) Even if Apple went as far as turning off non-essential background services, any gain would be lost as soon as the user opened up Chrome. That then brings up the question "Which is more power efficient? A single core slowly working through a huge backlog of instructions, running at full power to keep up, OR multiple CPU cores quickly chugging through the workload, then going to sleep." The answer will depend largely on the application and type of work the CPU has to do. So how do you create a power saver mode that works across applications and use case?
  • A very good idea. Even those that edit 4k video or run a compiler all day will spend a lot of the day on e-mail, or writing reports. Disable all but one of the four cores, and/or throttle all of them to 1Ghz will give you a much longer battery life and would be plenty fast for those tasks. Then if you DO need full Pro Power, you'll still have enough battery to do it. A widget in the Menu Bar giving you the ability to adjust performance on the fly would be ideal.
  • I don't really see the point, macOS already does a lot of things to reduce power consumption including reducing the power of the CPU/GPU when they're not being used for heavy tasks. For me this is something the OS should handle automatically, the OS can see what apps you're using and whether you're trying to max out the performance, or whether you're just doing very basic tasks.