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Apple is Allegedly Slowing Down Older iPhones With Degraded Batteries

Apple is Allegedly Slowing Down Older iPhones With Degraded Batteries

Posted December 11, 2017 at 1:21am by iClarified
Apple is allegedly underclocking the CPU of iPhones with degraded batteries to prevent unintended shutdowns and extend battery life, according to numerous reports on reddit.

Yesterday, reddit user TeckFire posted Geekbench results before and after replacing the battery on an older iPhone 6s. Prior to replacing the battery, the device achieved a single-core benchmark score of 1466 and a multi-core score of 2512. That's well below the average of 2330 and 3984. After the battery replacement, Geekbench reported a single-core score of 2526 and a multi-core score of 4456. TechFire's battery had a wear level of around 20%.

You may remember that a year ago Apple instituted a battery replacement program after iPhone 6s users reported unexpected shutdowns. At that time they claimed only a small number of users were affected due a manufacturing issue. The company then released iOS 10.2.1 three months later which was mysteriously able to fix unexpected shutdowns for 80% of affected iPhone 6s devices and 70% of iPhone 6 devices. It now appears as though the company started underclocking the CPU in iOS 10.2.1 if a battery in poor condition was detected.

"The increased power draw of the A8 and A9 chips will make your phone shut down when you don’t have enough voltage," says TeckFire. "This gets around it, by lowering the clock speed, so you don’t have to replace your battery, and can continue using your phone. I just wish Apple would tell us about this."

Other users have confirmed the same results. For example, reddit user TizzleStickz posts:
Before battery replacement:
1039 single and 1749 multi
After battery replacement:
2488 single and 4435 multi

Notably, even users with the iPhone 7 are reporting the same behavior; although, newer devices have efficiency cores which would make this less noticeable.

"I observed the same behaviour on an iPhone 7 (80% of design capacity). Fixed after replacing the battery," says goldcakes.

To determine if your device is being slowed down due to a degraded battery, download CPU DasherX (free) from the App Store and compare the CPU Frequency it displays with what's expected for your device.

Let us know if you've had a similar experience after replacing the battery on your device. Did performance improve?

Please follow iClarified on Twitter, Facebook, or RSS for updates.

Apple is Allegedly Slowing Down Older iPhones With Degraded Batteries
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Comments (23)
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Mars - December 12, 2017 at 7:42pm
I hope other party will do more research/confirmation on this , as I do not think it is a fair tactic.
Robert - December 12, 2017 at 1:18pm
Drop performance , that is sad. I have my iphone 7 for a year and i'm chargeing it somewhere between 2-4 days. Aproximatly 150 cicles for the hole year. Now my phone is 2/3 in performance and i dont think my battery has degraded so much. Maybe 3-5% at most. Thats just unfair.
CPup - December 11, 2017 at 5:24pm
I find it amazing that both battery tests were done at exactly 10:45 with exactly 80% battery. So... they what? They tested the old battery then shut down the phone, took it apart, replaced the battery, put it back together, rebooted it, then tested it again in less that 1 minute AND the battery levels happened to read the exact same? Result are a scam.
A-non-e-moose - December 11, 2017 at 5:30pm
Where is the screenshot you mentioned?
Core99 - December 11, 2017 at 5:45pm
First screenshot is grabbed from history, second one from bechmarks, Sherlock.
A-non-e-moose - December 11, 2017 at 9:08pm
And the second screenshot’s date on the bottoms is about 1.5 hours later than the first screenshot.
Andrey Upadyshev
Andrey Upadyshev - December 11, 2017 at 2:15pm
I've got a huge performance improvement after I've replaced the almost dead battery with a new one on my iPhone 6.
Leo H
Leo H - December 11, 2017 at 1:13pm
You always get half when the low power mode is on. Try putting any iPhone in low power mode and run benchmark and you’ll see the performance drop.
EzisArAbolu - December 11, 2017 at 10:16am
I have old battery results on my iPhone 6s 🤨
D4xM4Nx - December 11, 2017 at 10:01am
Update: Geekbench can also be used for the ones of us on iOS 10 or lower. No problem ;)
D4xM4Nx - December 11, 2017 at 9:54am
One of my iPhones which is older (iPhone 6), and definitely has a worn out battery is on iOS 10.2, unable to download the app - requires iOS 11. Some other options for testing, @iClarified?
SunGem - December 11, 2017 at 9:51am
The app in the screenshot and the app in the link is not the same?
mairymarakee33geo - December 11, 2017 at 8:32am
iPhone 6S CPU 600-911MHz but should be 1850Mhz Battery Design Capacity 1600/1715 (93%) Phone is sluggy and very disappointed.
Joe Dredd
Joe Dredd - December 11, 2017 at 7:06am
Not sure how reliable this is. I loaded this app a few times and the CPU was anywhere between 1600 and 1849 for a 6S which should be 1850
Thunk - December 11, 2017 at 6:23am
My iphone 6splus clocked at 1200mhz
curtixman - December 11, 2017 at 5:42am
Well it’s either that or offer customers a reasonable option to replace their batteries. Now that’s not gonna happen so... lowering the clock speeds it is then.
Bst - December 11, 2017 at 5:21am
Every iPhone with latest update (not latest released phones Ofc) runs very slow and lags... 1 year ago iPhone 7 was the best... right? Flyin thru IOS like Its a NASA computer... But try it now on iOS 11... becomes warm, lags, freezes Totally crap. Im NEVER gonna update My iPhone 7 from according to me best iOS ever, iOS 10
^PaX - December 11, 2017 at 5:21am
Kkkkkkk ,why you not try to put a iPhone X battery in your 5S ??????????
Cassandra - December 11, 2017 at 3:22am
Ab08 - December 11, 2017 at 3:08am
My 6s Plus has been extremely slow since updating to iOS 11, but the CPU frequency appears to be ok. Does that app show live frequency or max frequency for the CPU?
justabrake - December 11, 2017 at 1:39am
I just had my iPhone 5s battery replaced I was told by one Apple store that the battery is a hundred percent and doesn’t need replacing then 3 months later Apple tested it again at another location and said it should be replaced the whole phone was running wacky
gamerscul9870 - December 11, 2017 at 2:28am
Speaking of 5s phone battery and replacement, I upgraded mine with an se battery and it works like new again.
RWR - December 11, 2017 at 4:08am
That's not how that works. The connections are different.
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