iPhone 6 very slow with IOS 11 update

Replacing the battery is the only way for your phone to regain full performance - and that at all battery load levels.

I just had this done this morning. Now my phone runs at the nominal CPU frequency (1400MhZ) just like when it was new.

There is no "big mess" to solve. All Apple did was to gradually reduce CPU speed as the battery degraded to protect it and extend its life (and prevent sudden phone shutdowns).

MichelPM, yes I did.

Just before Apple admitted the CPU throttling and following the findings presented in this same thread, I ordered a new battery from ifixit and changed it myself (there is an old post around here where I explain this). Also I checked with CPU Dasher that my CPU went back to 1400MHz.

To sum up: The phone is performing much, MUCH, better, it is now usable, but usable is not what I expected from a 1000€ phone.

Besides a general clunkiness that is clearly noticeable in every aspect, and that was not there with iOS 10, which was butter smooth, I'm still experiencing the following issues:

-The keyboard is still suffering from mini freezes randomly, albeit it performs far better than it did before the battery replacement.
-Siri sometimes takes 10 to 15 seconds to start listening when long pressing the main button, even more when saying 'Hey Siri'. And many times she starts thinking for a while (after receiving whichever order I gave) and eventually just does nothing and closes.

-Fast forwarding (or rewinding) music or podcasts sometimes (many times) does the opposite thing.

-Many emails just don't load when trying to read them, I have to close the mail app and open it again.
-Sometimes the camera app takes ~10 seconds to open, others just 2 or 3. Taking pictures is also laggy.

-Youtube suffers from ~10 second freezes when receiving user input or when ending a video, and sometimes does not orient the screen properly (this could be youtube's problem, but it worked fine on iOS 10).

Maybe you are right and it all gets better when they let us opt out, maybe all those micro stutters is the throttling jumping in for a micro second, maybe ifixit batteries are just not as good as apple's, we will see.

In any case, I STRONGLY recommend to have your batteries replaced, the performance improvement is huge.

How do you use your iPhone?

Use is a factor, too!

Some users work their iPhone harder than others and that can have an effect on speed/performance of any iPhone due to limited RAM and CPU resources.

Have you tried a hard reset of your iPad by holding down both the Home and sleep/wake buttons simultaneously until your iPad goes to black and restarts with Apple logo, then release the buttons?

How much free data storage space is actually left on your iPhone.

iDevices need to maintain a minimum of 3 GBs, OR greater, free data storage space.

In Settings app, General settings panel, turn OFF Background App Refresh.

Settings app, under General settings, Reset panel, at the right bottom of the list, Reset All Settings.

In Settings app (NOT from the iOS Control Panel) turn OFF Bluetooth when not using any Bluetooth devices.

Also, in general, if you want a faster IDevice, on all of my iDevices, I turn off most of the iOS motion graphics eye candy, by simply turning ON Reduce Motion in Settings app, General, Accessibilty settings.

Make sure you aren't running scads and scads of background apps in the iOS 11 Control Panel/App Switcher.

If you are, you need to quit the bulk of these background running apps by tap and hold a finger on an app window in the switcher and slide your finger upwards to quit an app. You should be able to use more than one finger to quit more than one app window simultaneously.

Also, make sure you don’t have scads and scads of active website tabs running in the web browser.

If you do, greatly reduce the amount of active website tabs your web browser.

Good Luck to You!

agmillan86278 wrote:

Sorry, but that is not true.

Yes, it's absolutely true. iOS 11 used dynamic throttling on older batteries. iOS 11.3 allows you to turn it off. That's all. If it's turned off, you won't see the performance hit but your battery may drain rapidly or shut off unexpectedly. The only way to resolve that is with a new battery.

If you think your phone got faster with iOS 11.3 and you haven't disabled the throttling, then, the difference is not in the phone or it's behavior but in your perception.

1. I looked at the settings/privacy/analytics/analytics Data - there were a lot of program crashes and dumps on my phone. I ran a backup to Itunes and that removed them and seemed to help.

2. settings/location services/system services/ there are a lot of product improvements that are running on the phones. I turned off iphone analytics, popular near me, routing & traffic , significant Locations (this may impact some of your apps so test them after your turn these settings off) I didn't see any impact on the apps I use.

3. I went through my location sharing at settings/privacy/location services - and changed all the "background" refresh apps to "while using" or "never" to save on my cpu usage for apps that don't really need to update in the background when I'm not using them.

This is not exactly true. Replacing the battery will stop the phone from reducing CPU speed and improve performance a lot, to the point that the phone is usable again, but it will still be far from buttery smooth as it was with iOS 10 (at least with an iphone 6, maybe faster phones do fine).

I've had a slow, buggy iPhone since updating to iOS 11 and my problem was solved by completely wiping my phone. I said I was going to do this in earlier posts and just wanted to confirm that it did solve the problem. I did not restore from a backup since I was told that this would not resolve the issue. I set it up as a new phone and just re-synced with iTunes to get my music back and logged back into iCloud. Be sure to backup all your photos and videos and anything else you want to keep before doing this. I'm not saying this solution will work for everyone but it did for me.

You can't restore a previous version of iOS.

Apple is currently testing iOS 11.3, which will allow users to control the speed-throttling feature. This feature was implemented to prevent unexpected shutdowns by iOS devices with old batteries, but unfortunately it also degrades performance. When iOS 11.3 is released, users will be able to control whether this feature is turned on. You'll be able to choose the tradeoff between speed and safety.

If you want early access to this release, you can join Apple's iOS beta test program. The new feature was just made available to developers today. If Apple follows its usual pattern it should be available to the public beta testers in the next few days.

8 Days later my wife iPhone 6 still working like a new iPhone after the Apple replaced the battery for $29 bucks. I know it might be difficult for some folks to get to the apple store for the $29 dollar replacement, I had to drive an hour to get to the closet store, but i found a few things to do while i waited the hour for them to replace her battery. She is happy with the performance and no issues with slow downs.

Just checking in a few weeks after my wife's iPhone got a new battery, it has still been working like new, only costs $30 bucks, and a 1 1/2 wait at an Apple Store. She has an iPhone 6, her old battery had many cycles on it, and after the battery was replaced, no troubles, all apps work very fast,

I had the same experience. It's like night and day. I have my great old fast iPhone back. It just goes to show how much Apple messed up the operating system update.

I highly recommend anyone with performance problems upgrade to iOS 11.3 to get this fix.

That is what I was referring to in my post - for those (like where I live, where there is no cellular signal that use WiFi calling), but with additional battery drain - as a result of the phone increasing power output trying to reach a signal it will never get.

I only mentioned it here as the battery seems to have become the primary factor in why the phones are being slowed as a result of Apple's decision to arbitrarily do this for weakened batteries. So for those who have wifi calling as an option, it may help their battery by turning on airplane mode first, then reactivating wifi, for the purposes of reducing battery use relating to cellular use. Until everyone affected all go and get new batteries of course....😠

Here is a picture of my battery usage without Airplane Mode being on so you can clearly see what's at the top of the tree!

How old is your iPhone 6 or other iPhone 6 model?

It maybe time for a new battery under Apple’s reduced priced iPhone battery replacement program.

A new iPhone 6/6S/6S Plus battery will return your iPhone back to its normal performance and operation.

Andrew Shalit wrote:

So, this is not perception or imagination. iPhones with old batteries that were being throttled under previous versions of iOS 11 get an immediate performance improvement when iOS 11.3 is installed, even without a battery replacement. Of course, if you experience unexpected shutdowns or other battery problems, throttling will be turned on. At that point you can live with it, you can turn it off and take your chances with shutdowns, or you can replace the battery.

I believe that's exactly what I said to poster to whom I was replying.

Wait for the next iOS update . Apple has said to show details regarding your battery status. Then replace the battery to make your iPhone 6 faster for $29 .