iPhone 6s Low Power Mode

Low Power Mode allows iPhone users running iOS 9 to eke out more battery life when the battery is getting low. It doesn’t just pull this ability out of thin air, it causes iOS to turn off certain features like mail fetch, background app refresh, automatic downloads, etc.

What’s more, Low Power Mode significantly reduces the clock speed of your iOS device. We’ve seen before and after benchmarks with older iPhones involving Low Power Mode, but what about Apple’s just-released iPhone 6s? How much of an impact does Low Power Mode have on it?

Apple doesn’t actually list the percentage difference on its Low Power Mode support document, but a simple benchmark comparison paints a clear picture: Low Power Mode throttles your iPhone 6s processor significantly.

Low Power Mode iPone 6s Benchmarks

Before Low Power Mode vs After Low Power Mode

Just look at that Processor speed difference. What started out as a 1.85 Ghz Processor got down-clocked to 907 Mhz. That’s a 50.9% difference in clock speed. The Low Power Mode switch is thus a powerful throttle, probably more powerful than most thought.

With this in mind, it’s no wonder why Low Power Mode can save so much battery life. It’s basically taking your iPhone 6s back two generations to iPhone 5s territory:

iPhone 6s Low Power Mode iPhone 5s

It’s one thing to use Low Power Mode at times when you’re low on battery, but it’s a whole another thing to walk around with what is essentially an enhanced iPhone 5s in your pocket all day long. Maybe it would be different if Apple placed a toggle in Control Center to quickly enable and disable Low Power Mode, but I just don’t know why anyone would want to gimp their brand new powerful iPhone 6s for an extended amount of time.

Low Power Mode iPone 6s Benchmarks 2

Before and after

Earlier today I posted several ways to save battery life on the iPhone 6s, but none of those methods will be able to compete with throttling the processor by 50%. That’s where Low Power Mode has the upper hand over all other battery saving strategies.

Low Power Mode is great for those times when you need to make your phone last when it’s on its last leg of battery. But actually using your iPhone for an extended time while Low Power Mode is enabled just doesn’t seem like a good idea after looking at these benchmarks. Granted, the iPhone 5s is still no slouch, but why gimp such a beastly phone for long periods of time?

What do you think? Would you consider using Low Power Mode all day long?

  • Dany Quirion

    And no one beleived me

  • Torti_78

    Do Messengers like Whatsapp still work with Low Power Mode?

    • Merman123


    • rockdude094

      I don’t think you need a i5 to run whats app

  • David Ruiz

    This throtting stuff only works on 6S?

    • Merman123


    • Kyle

      iPhone 5 and up

    • David Ruiz

      I would like to see this kind of test on older devices (5, 5S, 6)

      • ranova

        no, it throttled my i5s as well

        i5s power saver single core gets a 945, multi gets a 1670

      • David Ruiz

        how is your experience with iOS 9 on 5S?
        the autonomy increase is worth to give up the jailbreak?

      • ranova

        no, not worth updating from 8.x with jailbreak. I only have it on ios9 because its a work phone

      • Pollsmor

        I could’ve sworn there was low power mode on my iPhone 4S running iOS 9 back when I used it. And I’m not sure, but I think low power mode can barely take enough power away than there even is. Glad I switched to a new SE.

  • RarestName

    My thoughts: this turns it into a bigger iPhone 5s with twice the RAM and better battery life. I do enjoy battery life, so it would be a healthy compromise.

  • AOGV

    iPhone 5S is still dope brah

  • Felipe Queiroz Drumond

    Why my 6s 64GB has only 55.6GB? This is 14.5% less space.

    • Chris

      iOS has to go somewhere.

      • Dean Johnson

        True, but on a 16GB the OS takes up less space, something around 3GB, while the 64GB models have 9GB less. Seems strange

      • Jayy

        Yeah I also thought it would take up less space like about the 3gb mark. But I’m okay with it cause the iPhone before I got my 6s only had 8gb well like 6gb really with the OS installed. Those were tough times! Lol

      • Felipe Queiroz Drumond

        The description is “capacity” and its value is 55.6GB. By capacity, I understand the total amount of data that the device can store, and it should be 64GB. My MBP, for instance, is 500GB and shows 499.08GB.

      • Chris

        You will never get the 100% capacity as advertised, a good example is typical hard drives for desktop’s and laptop’s. I purchased a Samsung 840 EVO 250GB and can only use 232GBs, I also have a 2TB WD Green which only allows 1.81TBs.

        Apple isn’t stealing your space, hard and/or storage drives are just made this way.

      • But the op brings up a good point. How come smaller capacity devices have less used space? Why does a 64gb use up more than a 16?

      • Chris

        I’m pretty sure my last post has the clue to that mystery.

      • you didn’t explain shit

      • Chris

        No need to get annoyed, the clue is in the hard drive size. I still think its pretty clear that larger HDDs contain less physical space than what’s offered.

        Another example, I have a 128GB iPhone 6, yet I only have 113.9GBs available.

        I can’t explain it any better than what I have already.


      • Chris

        A simple google search for ‘why do hard drives have less space’ will yeild the extended answer, only takes about 5 minutes.

      • Why does one have less space taken up than the other???

      • The storage is in 1000 multiplications instead of 1024. Therefore 64 * 1000 = 64000 / 1024 = 62.5
        Take of it the required space for iOS and the result is something similar to the 16 GB version’s storage if not higher by a little more.

    • Elias Chao

      The reason is because tech companies advertise their products storage with a 1000MB = 1GB conversion.

      The correct conversion is 1024MB = 1GB, if you do this conversion starting in bytes, then Kilobytes, and so on, your gadget end up loosing plenty of its advertised storage.

      The OS should take the same space no matter how much storage your device has.

      • Felipe Queiroz Drumond

        Guys, I am an IT person. I know this details about data. If 1GB is equal to 1,048,576KB (2ˆ20KB), the capacity of 55.6GB is equal to 58,300,825KB, which is, needless to say, not “64GB”.

        I would accept that “64GB” is equal to 61.03515.

    • Chase

      This is partially because of the storage used by the operating system (iOS), partially because of the formatting technique used on the hard drive (Solid state drive) and finally because they round to the nearest power of 2 (8,16,32,64,128).

  • sNick

    The big question is: which performance has the 5s in low power mode then? 😉

    • YoungRabbi

      hmm, Not sure, all I know is ios 9 runs horribly on my 5s in general.

      • Todd Sorensen

        That’s strange.

    • DevXav

      Thats an EXCELLENT question..

    • spoic


  • Kenan

    5s is a decent phone with decent performance.

    • DevXav

      Thats exactly what i was gonna say..

      Right now i own a 5S and even with power saving mode its a beast.

    • SkyFall

      I’d say its kind of a beast for its performance and considering its a 2 year old phone.

      Edit: Sure the pic is from iOS 7 but it still gets 2510 multi and 1423 single score in iOS 9. (The score below was a one-two time score).

  • Chris

    I personally don’t think this is a bad thing if you are going to an all-day event, for example. You typically you might be scrambling to find a recharge area whereas on Low Power Mode; you could continue with several hours of battery life to continue taking photos/video while retaining the ability to receive emails for instance.

    • raulortiz318

      Very true. I would turn this on all day while at Disney to continue taking pictures of the family.

      • Kaptivator

        I remember our time at Disney 2 years ago putting my phone in airplane mode to save battery. Now that I have upgraded to the 6s, I am looking forward to using this option on this years visit to Disney.

      • raulortiz318

        Awesome! Hope it works out for you, and have a great trip.

  • Franklin Richards

    O no. Poor iPhone 6s users.

  • JulianZH

    when i switched from i5 to i6, dont even notice any speed improvement.

  • ranova

    you guys make that sound like its the worst thing ever.

    I have the iPhone 6s for personal use (nights and weekends) and an iphone 5s for work. I only carry one with me at a time and I really dont see much difference in phone speed between the two.

    Not everyone plays demanding games or uses demanding apps all day long. Turning on battery saver all day probably would not be a huge difference to me

  • David J Delgado

    First world problems. No, but seriously, I tend to have low power mode on almost 100% of the time on my 6s and I haven’t noticed a single hiccup. It may be running at 5s speeds, but the differences don’t translate to the dramatic “50% decrease” in clock speeds. I guess the OS is just that good at managing its resources, unlike another mobile OS I know….

  • ranova

    low power on 5s is MUCH better than the 4s and even the 5.

    i5s power saver single core gets a 945, multi gets a 1670

    the i5 has a 710 single, 1274 multi

    i4s has a 215 single and 405 multi

  • That_Fruitarian

    Jeff sits at home all day and searches the web from his phone and he’s worried about battery life and ‘gimping’ his device… Lol

  • That_Fruitarian

    So I put my fully charged iPhone 6 Plus in lower power mode and watched a 30 minute video of Tesla unveiling the Model X and my battery only drained by 2% at completion of the video.

    I watched the video over wifi with Bluetooth and lte off. I’m very impressed with lower power mode.

  • All I know is that without low power mode my 5s drops to 50% battery within a couple of hours with it turned on it lasts the entire day. Whatever low power mode is doing it’s working.

  • Ryan Archer

    For anybody with an older iPhone that may be interested, I tested this on my 5c (don’t make fun of me. I love this phone, although I can’t wait to upgrade to the 6s) and the geekbench scores went from 683 single core and 1207 multi core on normal power to 496 single core and 892 multi core on low power. There’s some lag, sure, but for somebody who’s not a power user it’s definitely acceptable for times when you may need a bit more time before charging.

  • XcodeGhost

    At least the iPhone 5s isn’t like the iPhone 4S all laggy.

  • rain rocket

    5S was the best phone in the world in its size!

  • Chris

    No. No one beleived you.

  • Dan

    Kind of ridiculous that people have to consider doing this. Apple should of just went with a bigger battery.

  • They still update on background even if the low-power mode is activated..

  • Alex Grillo

    It’s like owning a 15in MacBook Pro: you use all 4 cores and peg that dedicated GPU maybe 5-25% of the time, and you know when those times are. I need both 64-bit cores and 2GBs RAM to play War Tortoise and GOF2, not to check email and browse the web. If I’m going a whole weekend without a charger, Low Power Mode for the win!