M2 MBA's Big Superpower: Efficiency Cores = Incredible Battery Life on Low Power Mode

[mrmister]

I realized yesterday that my new M2 MBA has a superpower I don’t see people here mentioning, and it is a game changer.

The M2 chip’s big advance isn’t in raw horsepower—the performance cores, though it is about 20% faster than an M1.

It’s the EFFICIENCY cores, which Apple focused on for this chip.

(Yes, I know this is a Max Tech video. They annoy me as well—but they do all the tests you need to watch to hear about how this is.)

TLDR: If you use Low Power Mode when on battery, you get 2/3 of the power…and increase your battery life an incredible amount, far outpacing what the M1 can do on Low Power Mode.

It’s a game changer. I haven’t been able to do benchmarks yet, but I think for low-key tasks that my MBA is often doing (posting on these forums, reading my mail, working on documents) it is going to do something like double the battery life.

And as you can see from the performance tests—you lose very little power!

THIS is the reason to get the M2 over the M1. THIS is what we should be focusing on. THIS is the superpower of the M2 chip, and where the emphasis went in designing it.

Try it out, and report back how it’s working for you.

 

[Apple_Robert]

https://forums.macrumors.com/threads/max-tech-running-the-m2-macbook-air-on-just-the-efficiency-cores.2352517/page-3?post=31287360#post-31287360

 

[mrmister]

I read that thread, but I haven't seen any of it even mentioned in any of our ongoing discussions of m2 vs m1!

 

[Apple_Robert]

I read that thread, but I haven't seen any of it even mentioned in any of our ongoing discussions of m2 vs m1!

That is probably because most of the time, people have easy access to charging. And when that isn't the case, the M2 already provides better battery (depending on use) than the M1. It is a nice feature but, not the day to day game changer the Max Tech painted it to be.

 

[mrmister]

"It is a nice feature but, not the day to day game changer the Max Tech painted it to be."

Do you have any data to back that? I ask because those voltage rates are so low—I'm going to be doing testing all week, I don't see how it won't incredibly increase my runtime at low performance cost.

"That is probably because most of the time, people have easy access to charging."

No offense, but this is a dodge. Battery life is a top concern for all mobile devices—it seems curious that no one is talking about the main advantage that the M2 chip was designed to deliver.

 

[sjperformance]

I enjoy my m2 air. Last laptop purchase was 7-8 years ago (dell). Hated the battery life on that thing. Last year got my step son a m1 air. I charge my air 2 like 2-3 times a week. The battery life on this thing is awesome considering everything I do on it.

BTW I’m tired of max tech current videos of next iPhone. Like everyday a new video on the same info just with different words. He puts me to sleep.

 

[Apple_Robert]

"It is a nice feature but, not the day to day game changer the Max Tech painted it to be."

Do you have any data to back that? I ask because those voltage rates are so low—I'm going to be doing testing all week, I don't see how it won't incredibly increase my runtime at low performance cost.

"That is probably because most of the time, people have easy access to charging."

No offense, but this is a dodge. Battery life is a top concern for all mobile devices—it seems curious that no one is talking about the main advantage that the M2 chip was designed to deliver.

No, I don't have data to back up my personal opinion stated as such. I also haven't dodged anything. Max's video states that LPM is some kind of secret mode when it isn't. The option is easy to see and turn on if one wishes. More battery life is nice but, as I stated, a lot of people have access to charging and with the M2 already having great battery life, LPM isn't the game changer.

 

[CE3]

I think we’re spoiled. Even if the M2 Air gets 50% more battery life (a claim I’m a little skeptical of) both the M1 & M2 models offer some of the best battery life you can get from a Mac or Windows laptop on the market right now. So both would be excellent options for people who prioritize such things.

 

[mrmister]

"Max's video states that LPM is some kind of secret mode when it isn't. The option is easy to see and turn on if one wishes."

I think you're being pendantic—if that's your whole complaint, it's just that you don't like their titling. I really wish we'd stay on the big news that M2 efficiency cores are AMAZING.

"No, I don't have data to back up my personal opinion stated as such."

I mean, ok...but their video takes time to detail the voltages and exactly how much power it uses, and the difference between an M1 Air and an M2 Air. I think saying "it's no big deal" should require more than just "I have an opinion".

"I also haven't dodged anything."

I mean, you think battery life isn't important, which seems bonkers to me, but you are commenting here a lot?

 

[mrmister]

"Even if the M2 Air gets 50% more battery life (a claim I’m a little skeptical of)"

I am too, but the voltages check out. I'll know more after I use it this way all week.

 

[boak]

How much "true" extra battery life (extra work done) though? I'm assuming you take longer to run the same workload.

 

[mrmister]

“How much "true" extra battery life (extra work done) though? I'm assuming you take longer to run the same workload.”

Depends on what you’re doing, but in my experience the lighter you use it, the more you’d get.

 

[Wokis]

The efficiency cores are definitely really good. But I don't really see much use of LP-mode outside of rare scenarios where I HAVE to stay away from a power plug for a ludicrous amount of time.

You have to recognise that when the M2 is doing a prolonged heavy workflow, it automatically goes into something that could be seen as a low power mode anyway, to keep thermals in check. It's amazing how well it still performs when in it, but keeping LP-mode on from the start would just have me lose out on initial burst performance and also general system response and snappiness during more common short burst workloads.

 

[mrmister]

I basically don’t do anything stressful to my computer, ever. So I’m very interested.

 

[mrmister]

“but keeping LP-mode on from the start would just have me lose out on initial burst performance and also general system response and snappiness during more common short burst workloads.”

I hear this, but so far in my experience I can’t tell the difference at all in response or snappiness. AT ALL.

 

[unrigestered]

you can always safe even more battery... question is: at which point it is becoming counter productive to you

i don't know which method MaxTech are using, but i think (as i actually never used it myself) that the "save battery" mode is also using only 30fps refresh rate, making everything look and feel more sluggish

you could also lower screen brightness down to a point were everything is only barely visible anymore - but how great it is to work on that is another story

or simply always only use one app with one tab open at a time

and there surely are ways to downclock the system to let it run capped at 500MHz or so

disable WLAN, Bluetooth, etc...

....

 

[jdb8167]

The efficiency cores are definitely really good. But I don't really see much use of LP-mode outside of rare scenarios where I HAVE to stay away from a power plug for a ludicrous amount of time.

You have to recognise that when the M2 is doing a prolonged heavy workflow, it automatically goes into something that could be seen as a low power mode anyway, to keep thermals in check. It's amazing how well it still performs when in it, but keeping LP-mode on from the start would just have me lose out on initial burst performance and also general system response and snappiness during more common short burst workloads.

Watching package power bursting to over 30 W and gradually declining to under 8 W under load is pretty remarkable. You would think performance would decline by 1/2 or more but it doesn’t. Some kind of Apple magic.

 

[a.phoenicis]

I love my M2 MBA, but I’m highly doubtful that this approach would yield significantly better battery life than normal. Why? Because

1. macOS is already good at utilizing the efficiency cores when intensive computing is not needed.
2. For low-cpu-intensive uses, I doubt that the difference on apple silicon is that great compared to the power draw of the display & backlight, Wi-Fi radios, etc.

Ie: even if you’re running the efficiency cores only, you’re still using Wi-Fi at full power and the display at full resolution.

Will you get better battery life on LPM? Sure. Hours and hours more? Nope.

 

[BornAgainApple]

I like my M1 Air so much, I just bought a second to replace my daughter’s pathetically slow Intel Air. I would have bought the M2 because of her workload in the medical field, but the $200 difference more than offsets the efficiency gains and there’s not much difference in performance between the two chips.

 

[mrmister]

“the $200 difference more than offsets the efficiency gains and there’s not much difference in performance between the two chips.”

The statistics make clear that there is a big difference.

 

[mrmister]

Will you get better battery life on LPM? Sure. Hours and hours more? Nope.

Maybe! But I will say, I posted hard data at the top in that video—it makes super clear just how much voltage is saved. Suggest you actually watch it.

That said, you might be right! That's why I'll be running my own tests this week. But I find with the data in that video it's clearly substantial, but I'm open to it turning out to be not a big deal. But I do think it will be a big deal, just based on those voltages—I used to underclock chips, and the savings are real.

 

[mrmister]

(Also I changed the thread title to make it less clickbaity, I don't want to trash the M1 MBA, I just wrote the first title I had thought of.)

 

[imnotthewalrus]

(Also I changed the thread title to make it less clickbaity, I don't want to trash the M1 MBA, I just wrote the first title I had thought of.)

I'm glad I saw this post before replying to #20. I am truly glad you love your M2 Air, and obviously it's an "upgrade", but to say there is a "big difference", is subjective to what people are going to DO with it. I have a base model M1 MBA and the heaviest app I use is Logic Pro, and the M1 is faster than the fully maxed 2015 MBP 15" (a $2500+ machine) that it replaced at rendering complex compositions.

So, again - I'm glad you like your M2...just beware of adding hyperbole to your comments.

 

[mrmister]

“but to say there is a "big difference", is subjective”

It’s not. I posted an entire rundown of the efficiency cores. If you want to discuss particulars, let’s. But no, it’s not “subjective”.

Also the way people on this forum use “subjective” like it’s some sin makes me feel like I’m talking to Ayn Rand fans. 😳

 

[imnotthewalrus]

“but to say there is a "big difference", is subjective”

It’s not. I posted an entire rundown of the efficiency cores. If you want to discuss particulars, let’s. But no, it’s not “subjective”.

Also the way people on this forum use “subjective” like it’s some sin makes me feel like I’m talking to Ayn Rand fans. 😳

That tells me all I need to know about you. Have a nice life.