iOS 9 beta 4 performance and battery thread!

[lagwagon]

Look at it this way.

Using a OS X as an example. You have a program running and you just click the red X to close the window. The app still shows the dot below it in the dock showing that it's still active in ram for later use and won't require a full relaunch (app switcher in iOS works in the same fashion.) Times that by 20, 30, 40 apps all being left in background (ram) so it can launch quicker at a later time. Even a couple days of sitting in there it should still launch quicker than a fresh relaunch. This means data is still being stored and resources being used (wether the app is actually doing something or not) This over time and as more and more apps get placed in this state clog up your resources cause the OS and anything to take that performance hit.

I could be way wrong, but that's how I see it.

Then there is the notification widgets. The more you add the more things are always running.

 

[Luis Mazza]

I see no point to leaving apps in the switcher of you only use like once a day, every couple days or even once a week. I get that it uses more battery if you open and close that app often enough. But I'm sure there is a breakpoint of how long an app sits in the switcher vs closing that negates gains of leaving it in. Also some people see apps using ridiculous background usage in battery even when not used in a while, so I don't think things get fully "suspended" after X time.

The apps in appswitcher are only a placeholder, but if there's enough RAM, and if they behave the same way as foreground when on background, then they will still run after some time. That's also why the Air 2 is suffering more with battery issues: it has double the RAM.
Apps should behave better when on background, or Apple should really freeze them after like 60 seconds.

 

[MrGuder]

So this is my 2nd full day with the new beta 4 on my iPhone 5, I'm not sure yet how my battery is doing, I still want to give it a few more days but here are my results on day 2

I always charge my phone overnight, unplug it about 7:00 am with 100% battery, right now I am currently at 8% battery left and my usage is 3 hrs 52 mins, standby 15 hr 35 mins. I'm basically using the phone like I normally did with iOS8 except that I am using the News App more on the beta. So I think I'll probably get a little over 4 hrs usage, wonder if this might get better as the phone adapts to the new beta?

There is some delay in opening some apps but it's not anything I can't live without and all my apps work, music player works fine. Most of all I really like the low power feature when you get to 20%, that I feel is worth using the beta 4 at least for me. I'll probably stick with this beta unless something bad happens but cell connections with Verizon is much better on beta 4 for me.

 

[Yongkykun]

News360 apparently sucks the life out of my iPhone 6 (128GB model) on iOS 9 Beta 4. This screencaps tell the tale.

Starts out at 93% (fully charged around 10am), reading some news for a bit and noticed the battery percentage drops to 89% and I actually saw it dropping by 1% in almost 2 second increments. By the time I stopped reading it stayed at 78%. Amazingly enough, once I'm out of the app the battery stays at a steady 77% for over half an hour and the back of the phone was warm. Not much but it's quite noticable.

 

[Merkie]

Beta 4 has better performance and battery life than beta 3, but still not as good as 8.4.

 

[Abazigal]

I went out on a school trip with my class today and my iPhone 5s was laggy as hell. Even the simple act of launching the camera app from the lockscreen was slow and stuttery. My phone even froze on me when I launched maps to navigate the route back to school.

Which is odd, because my phone is still normally quite smooth at home and at work (but not as smooth as the first public beta). I noticed that data was weak. It seems that the phone's attempt to search for a signal seemed to be impacting performance significantly.

Because when I got home, my phone is now functioning quite well.

 

[C DM]

Look at it this way.

Using a OS X as an example. You have a program running and you just click the red X to close the window. The app still shows the dot below it in the dock showing that it's still active in ram for later use and won't require a full relaunch (app switcher in iOS works in the same fashion.) Times that by 20, 30, 40 apps all being left in background (ram) so it can launch quicker at a later time. Even a couple days of sitting in there it should still launch quicker than a fresh relaunch. This means data is still being stored and resources being used (wether the app is actually doing something or not) This over time and as more and more apps get placed in this state clog up your resources cause the OS and anything to take that performance hit.

I could be way wrong, but that's how I see it.

Then there is the notification widgets. The more you add the more things are always running.

iOS isn't designed that way. Apps in the app switcher are mostly not running and unloaded from memory (as in basically closed) when the memory they are using up is needed.

 

[Hatton920]

That might be true but some apps do seem to cause problems. I received a Facebook message the other day. I was only in the app for under a minute yet according to the battery screen it used 2.5hrs of my battery in the background and I don't allow messenger to background refresh.

 

[lagwagon]

iOS isn't designed that way. Apps in the app switcher are mostly not running and unloaded from memory (as in basically closed) when the memory they are using up is needed.

Then where are these "snapshots" being stored? You say "mostly" not running which means still somewhat in memory. Wouldn't the snapshots disappear if the memory of that app was using is taken for something else then? And wouldn't the whole battery benefit (of launching from memory vs fresh relaunch) go completely away once that happens?

The theory I'm trying to bring up is the people who leave literally every single app installed in the app switcher are probably in most cases the ones who see slow/laggy/unresponsive OS. (I'm not talking like 10 apps in there, I'm talking the people who leave it all like 20, 30, 40, 50, and so on.) All those "snapshots" are using something, otherwise you wouldn't see it.

It's like someone carrying a backpack (app switcher). You add things in this backpack (apps) to be readily available (memory) but the more you add the heavier the backpack gets, thus slowing you (the OS) down.

 

[imagineadam]

Then where are these "snapshots" being stored? You say "mostly" not running which means still somewhat in memory. Wouldn't the snapshots disappear if the memory of that app was using is taken for something else then? And wouldn't the whole battery benefit (of launching from memory vs fresh relaunch) go completely away once that happens?

The theory I'm trying to bring up is the people who leave literally every single app installed in the app switcher are probably in most cases the ones who see slow/laggy/unresponsive OS. (I'm not talking like 10 apps in there, I'm talking the people who leave it all like 20, 30, 40, 50, and so on.) All those "snapshots" are using something, otherwise you wouldn't see it.

It's like someone carrying a backpack (app switcher). You add things in this backpack (apps) to be readily available (memory) but the more you add the heavier the backpack gets, thus slowing you (the OS) down.

The snapshots are stored to the phones hard drive space. They take up hardly any space. I've seen the folder for them in ifile when I was jailbroken and they just get overwritten each time the app is left. They aren't stored in the ram. It doesn't make a difference if there are 10 or 20 or 50 apps in the tray. iOS closes what it needs to when it needs ram. The processors and ram are so fast now you don't really see a difference whether or not if it has to remove an app from memory or from a fresh start. You might see better performance on an iPhone 4 if you close apps but every phone after that is negligible or no difference in my experience.

 

[Hatton920]

Something not right with messenger. Shouldn't iOS suspend this app when not in use?

 

[C DM]

Then where are these "snapshots" being stored? You say "mostly" not running which means still somewhat in memory. Wouldn't the snapshots disappear if the memory of that app was using is taken for something else then? And wouldn't the whole battery benefit (of launching from memory vs fresh relaunch) go completely away once that happens?

The theory I'm trying to bring up is the people who leave literally every single app installed in the app switcher are probably in most cases the ones who see slow/laggy/unresponsive OS. (I'm not talking like 10 apps in there, I'm talking the people who leave it all like 20, 30, 40, 50, and so on.) All those "snapshots" are using something, otherwise you wouldn't see it.

It's like someone carrying a backpack (app switcher). You add things in this backpack (apps) to be readily available (memory) but the more you add the heavier the backpack gets, thus slowing you (the OS) down.

Right, they are in memory but generally not running or using up resources essentially (short of some running for a few minutes in the background after you use them, and very few apps like Skype which have certain abilities like VoIP that can stay in the background longer).
So basically there isn't much need to clear them out of the recent apps list as either they are still in the memory and would be quicker to get back to, or they aren't in the memory and it's not much different then launching them from their usual place (which means no need to spend the time or effort to specifically always clear them from the most recent apps list just because essentially).

 

[DrBlueBox]

Something not right with messenger. Shouldn't iOS suspend this app when not in use?

Facebook and Messenger are very badly coded apps. Add that on top of a brand new iOS and you're going to get problems with them

 

[dcp10]

http://www.speirs.org/blog/2012/1/2/misconceptions-about-ios-multitasking.html


This is absolutely the best article I've read on iOS memory management. It explains it quite well and I've never seen anything contradictory since it was written.

Regarding FB, I remember reading a couple of years ago that it was one of those apps which can run in background indefinitely, and I presume Messenger is the same.

I stopped using the FB app and switched to the web version instead. I can't say that my battery life shot way way up, but I do think there was a noticeable improvement.

 

[lagwagon]

http://www.speirs.org/blog/2012/1/2/misconceptions-about-ios-multitasking.html


This is absolutely the best article I've read on iOS memory management. It explains it quite well and I've never seen anything contradictory since it was written.

Regarding FB, I remember reading a couple of years ago that it was one of those apps which can run in background indefinitely, and I presume Messenger is the same.

I stopped using the FB app and switched to the web version instead. I can't say that my battery life shot way way up, but I do think there was a noticeable improvement.

That was written for iOS 5. While I won't argue it, it is possible things have changed since then. (Like him mentioning you don't see the currently active app in the switcher when you clearly do now (it's the top most one you see next to the home screen card.))

As for the five types of apps that can run indefinitely. It's also quite possible my "theory" is right. Because someone who literally never cleans out the switcher and has every single installed app in there that out of those 20, 30, 40, 50+ apps they have quite a few that do run indefinitely and would cause slow down.

 

[Coupz]

I believe Facebook and messenger are using the VoIP feature. VoIP apps can run longer in the background also like Skype.

 

[DrBlueBox]

I've got a 6 Plus and when I leave all my apps in the task switcher, the phone is noticeably slower and less responsive

 

[nerdriot]

Just chiming in with what I've noticed from PB2, performance and battery-wise:

• Animations are much smoother, especially the control center. In PB1, it dragged like it didn't want to open at all on my iPhone 6.

• Suggestions is a little buggy. I can see the top part of icons underneath the first section (see image).

• Battery life: not so great. This has always been the case with me though on Verizon, and I don't know why. But battery life compared to 8.4 isn't great. I went from averaging 6.5 hours of usage a day to around 5 hours a day, with no change in usage. The only way I can squeeze out that extra 1.5 hours is by turning on low-power mode.

All in all, it's a beta. I think performance and battery life will improve greatly not only in future updates, but also when apps are developed for iOS 9.

 

[lagwagon]

Just chiming in with what I've noticed from PB2, performance and battery-wise:

• Animations are much smoother, especially the control center. In PB1, it dragged like it didn't want to open at all on my iPhone 6.

• Suggestions is a little buggy. I can see the top part of icons underneath the first section (see image).

• Battery life: not so great. This has always been the case with me though on Verizon, and I don't know why. But battery life compared to 8.4 isn't great. I went from averaging 6.5 hours of usage a day to around 5 hours a day, with no change in usage. The only way I can squeeze out that extra 1.5 hours is by turning on low-power mode.

All in all, it's a beta. I think performance and battery life will improve greatly not only in future updates, but also when apps are developed for iOS 9.

Reboot (power + home) to fix the visual bug in your image. I've had it a couple times and doing that fixed it.

 

[nerdriot]

Reboot (power + home) to fix the visual bug in your image. I've had it a couple times and doing that fixed it.

Thanks, I'll give that a shot.

 

[nerdriot]

Reboot (power + home) to fix the visual bug in your image. I've had it a couple times and doing that fixed it.

So I tried that and while it didn't work, doing "reset all settings" did work. It also fixed a couple of other small nagging issues. Weird...

 

[GreyOS]

I know people here will say Facebook has always used a lot of battery, but does anyone think that bad battery experiences on iOS 9 could in part be down to an incompatibility with Facebook which exacerbates the problem?

In the last 24 hours, Facebook has only been on screen for 3 minutes, yet it's been running in the background for 8.4 hours and is responsible for 40% of battery use in that period. I don't even have Background App Refresh turned on, so it is using one of the other privileges to run in the background... but which? I think it's a bug with iOS 9...

 

[VSMacOne]

Does leaving apps open really make an impact on performance? I thought this was disproved a long time ago. The issue is that it's a beta build, so performance will vary build by build.

I think people want to make you believe that having a bunch of apps open doesn't affect anything, but if you ever take your phone to the Genius Bar the FIRST thing they do is ask when was the last time you closed apps and restarted your phone. I've had two different geniuses do that same thing when I've taken my wife's phone in with issues and I've heard others tell customers the same thing in the Apple Store.
So Apple is SAYING one thing, but DOING a totally different thing at the Genius Bar.

 

[loftiness]

I think people want to make you believe that having a bunch of apps open doesn't affect anything, but if you ever take your phone to the Genius Bar the FIRST thing they do is ask when was the last time you closed apps and restarted your phone. I've had two different geniuses do that same thing when I've taken my wife's phone in with issues and I've heard others tell customers the same thing in the Apple Store.
So Apple is SAYING one thing, but DOING a totally different thing at the Genius Bar.

Actually it's a bit more complex than that, there's a good reason Genius clear app from app switcher for troubleshooting (although arguably they might be doing it too much), while in normal usage it should actually be better if you left app in app switcher. Note that I didn't say leaving the app "open".

The reason being there's low correlation between the fact that an app shows in app switcher, and the app being in memory or running. Given the limited resources, iOS automatically manages memory, quitting apps that hasn't been used recently when more memory is needed, but app switcher only shows the last couple of app used, regardless of whether the app is in memory or not. If this works correctly (and hopefully it does most of the time), then when you remove app from app switcher, iOS will force the termination and clear the memory even though it's not short on resources. This actually leads to worse battery life and performance because if the app is a frequently used one, it will be kept in memory more often after you left it, and when you switch back or open it again, it doesn't have to start all over again. If you force its memory to be purged it has to do the extra work to start again every time, using more time and energy.

Now it's also possible that one of your app's (or its background process) will go rogue, in which case you have no choice but to forcibly terminate it by removing from app switcher. It's entirely valid as a troubleshooting measure. Although if it's not even running right now that does nothing, or just purge the memory, as a user you can't really tell for certain unless you hook it up to Xcode and examine the processes in instruments.

TL,DR: genius bar clear your app switcher (which may or may not actually "close" the app) as a valid troubleshooting measure, which you can also do when something doesn't feel right, however doing it regularly most likely lead to worse battery life and performance.

on topic: my 5S has worse battery life on beta 4 than beta 3, not sure why... i would say it went back to beta 2 level, barely enough for a full day :s

 

[shandyman]

Something not right with messenger. Shouldn't iOS suspend this app when not in use?

I've gotten to the end of my work day with 50% less battery on my iPhone than usual and the only abnormality is Facebook Messenger being active in the background for 10.4 hours today! Weirdly, I had no issues with PB2 until now.

Also, oddly my Apple Watch was down to 5%, normally it's at 60% at that time. Something very weird going on with PB2 today for me.