iPhone 6 plus still Slow after new battery

I have the same issue although with a third party battery on an iPhone 6s Plus the bench mark scores are equivalent of an iPhone 6.

What I would like to know is disabling the throttling through a plist edit.

I can echo your experience. So frustrating. All over the news and internet there's the same message, a new battery = improved performance. WRONG! My iPhone 6+ has a brand new OEM battery. The end result is great battery life and the exact same horrible performance (maybe even worse): I still can't use Siri, apps lag to the point of being useless, can't play any CPU intensive games, camera lags and crashes, takes about 45 seconds for music to start playing and the keyboard is so laggy I can finish entire text messages before the first keystroke is registered. I've reformatted the phone so many times that I'm tempted to do a factory refresh and not upgrade the iOS and use whatever apps are still compatible with whatever version of iOS that is.

I paid $1,400 CAD when I bought my phone a few years back and Apple has nearly completed its transformation into a paper weight. I will be switching to Android and I've been an iPhone user since the iPhone 3GS. Well done Apple!

All, I just had an interesting realization. I read an article that suggested that if your phone is below 81% battery the performance will be significantly decreased. I downloaded a free iphone benchmark app and battery life and here are my findings:

As a starting benchmark per the benchmark site, see link below, the avg. PassMark rating for an iPhone 6 Plus is 4,569 (keep in mind the most popular iOS was 8.1 that helped generate this avg.) Here are my scores with the corresponding battery life:

Battery: 63% Charging iPhone while running testing: Yes PassMark: 1,644

Battery: 69% Charging iPhone while running testing: Yes PassMark: 1,865

Battery: 79% Charging iPhone while running testing: Yes PassMark: 1,908

Battery: 91% Charging iPhone while running testing: Yes PassMark: 2,815

Battery: 100% Charging iPhone while running testing: Yes PassMark: 2,625

I wasn't expecting lower performance at 100% vs 91% so I unplugged and kept testing:

Battery: 100% Charging iPhone while running testing: No PassMark: 3,063

Battery: 98% Charging iPhone while running testing: No PassMark: 2,963

Battery: 97% Charging iPhone while running testing: No PassMark: 2,949

The range in performance is dramatic; 1,644 to 3,063 is around 86% increase in PassMark score and can be considered an 86% increase in performance. Real world result, my phone was working almost normally again. Siri worked for the first time in a long time with limited lag.

Conclusion: To have about 2/3rds the performance of your iPhone 6 plus the day you got it you need to keep your battery nearly fully charged and running on battery rather than being charged. Ridiculous considering I have a brand new battery so I suspect that Apple is blindly slowing down older phones regardless of battery health. If anyone has an original battery please do these tests and report back - I wish I had done a before and after to compare.

Cheers!

Link:

PassMark iOS, iPhone, iPod Touch, iPad Benchmark for Apple iPhone 6 Plus

My iPhone 6 Plus is still dog slow after replacing with brand new battery, and reinstalled fresh iOS 11.x (newest version). Siri runs so slow it’s unusable- huge lags. My apps all launch really slow, my camera app is almost unusable lags too much takes a long time to take a picture. My Safari runs slow and hangs as well forcing me to quit and relaunch Safari to gain control again- problem is the search field cannot be used- get’s stuck cannot type to it. Also, all the features of the iOS are slow, even the rotating which get’s graphics glitches when rotating and sometimes lags 5 seconds before rotating, swiping to bring up control panels and widgets panels is do slow too and causes a lot of failed swipes. I replaced my battery with before I originally installed iOS 11, and all this happened. This is more than just the software reacting to a low battery. My battery was never low. And, I’ve tried reinstalling several times from a wiped out flash drive, basically doing a full recovery 2 times and it didn’t help. Still slow. Frustrated, and feel like I’ve been lied to.

I think there is something wrong with the iPhone 6s Plus firmware as I just checked my iPhone 5s running the latest version. 56% battery ware. Cpu dasher shows it’s running at 1175mhz so I don’t believe it has to do too much with the battery.

I'been had an iPhone 6 from new, shortly after release; the last reasonably priced iPhone. A loyal customer of a decade. On the latest iOS, you type something in Safari and it only appears a few seconds later. It's laggy and slow, but the hardware has never changed from when it was lightning fast, only the software. The phone is almost unusable. I'd like to go back to iOS 8 which worked pretty well. Just give me the latest security updates, no battery saving rubbish Or other interference. If Apple don't start allowing downgrades of iOS pretty soon, this is for sure the last one I'll ever buy/own. My friends are furious too.

evergreens197 wrote:

If Apple don't start allowing downgrades of iOS pretty soon, this is for sure the last one I'll ever buy/own.

Goodbye.

evergreens197 wrote:

My friends are furious too.

Mine aren't.

Thanks for sharing. I'm re-running the tests now and I'm getting inconsistent performance ratings, you may be right about the quality of the benchmark application.

Regardless of performance testing, my real world experience has been that my phone is only usable if my battery charge is between roughly 85% to 100%, if it drops below 85% it becomes frustratingly laggy and unusable. I'm trying to make it to the next iOS update which I've been made to believe will allow users to turn off the feature that slows down "old" phones. I don't have high hopes for this issue to be resolved with the next iOS update but do have hopes that all the class action lawsuits will motivate Apple to resolve it soon.

Same here. I've done everything. I don't believe this is anything to do with the CPU slowdown/shutdown issue (my Geekbench results are within the expected rage for the iPhone 6), it's to do with iOS 11 being a buggy ton of cr*p. I've never had these problems on iOS 10 or any previous version of iOS on my iPhone 6. I've never been so close to smashing my iPhone it's so destroyed by this garbage update. Worst iOS I have *ever* installed!

I have had a very similar experience. New battery in my iPhone6 made no observable difference in lag and start up times. This is very frustrating. I have all the latest updates so can't blame anything on old software.

clmu wrote:

I have had a very similar experience. New battery in my iPhone6 made no observable difference in lag and start up times. This is very frustrating. I have all the latest updates so can't blame anything on old software.

All I can think of is that SSD read speeds inevitably slow down over time. It's unavoidable because flash memory is inherently subject to errors as the "floating gate" breaks down from repeated erasing. Once errors creep in, the SSD controller needs to use error correction to determine the correct data, and that takes time.

Could also be due to a performance hit from the latest iOS updates. Have you tried one of the benchmarks like Geekbench? I bought Geekbench 3 (I think 99 cents) and can use that to check against reference scores. It also is accessible through all my iOS devices on the same Apple ID. As a benchmark it's really closely testing the CPU and SSD.