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Voluntary Multi-tasking? Battery DRAINS.
- Thread starter mediaboy
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So one or more of the 17 Apps in your task-switcher bar seems to drain the battery... What Apps are we talking about here? (Be specific: it helps to diagnose the problem.)
Ever since I started using Camera+ and now Hipstamatic I've noticed batt life being shorter.
When I took it to the Apple Store this past weekend the MacG told me to kill EVERY SINGLE APP in the Multi-Task bar. I asked him why and he just said "DO IT", um ok. Since doing that I noticed my batt life is a tad better. Who knows...
When I took it to the Apple Store this past weekend the MacG told me to kill EVERY SINGLE APP in the Multi-Task bar. I asked him why and he just said "DO IT", um ok. Since doing that I noticed my batt life is a tad better. Who knows...
But Skype for example runs in the background insofar as someone can ring you but only if it's in the mutlitasking bin? TomTom continues to give directions in the background as another example. I have 3 friends who were complaining about terrible battery life since iOS4 upgrade. When I told them to clear out their background lists that had built up over weeks of use, suddenly they find it improved.
When you restore from a backup, you are restoring software and settings saved from older, different hardware. That being said, if you had a 3G and now have an iPhone 4, you are not going to be able to optimize to full battery potential because the software still kind of thinks its running on a 3G, not using the newer, power-saving technology.
Its always better to set a new iPhone up as new.. Though half the time I just end up restoring because its easier.
nope, people being able to call you on skype is actually down to push notifications. it's only running in the background if you're on a call.
as for tomtom, it's not running the whole app in the background, just 2-3 API's from the app.
Same here. IMO restoring as new on every new iPhone I get defeats the purpose of having an iPhone.
How did this thread become so long?
You restored from backup from a [3G] to an [4] and you're surprised by your poor battery life? I commend your faith in Apple here, but...
Restore as new. Restore as new. Restore as new.
There. I took care of the next three lazy people that come on here about battery life.
You restored from backup from a [3G] to an [4] and you're surprised by your poor battery life? I commend your faith in Apple here, but...
Restore as new. Restore as new. Restore as new.
There. I took care of the next three lazy people that come on here about battery life.
Not entirely true. If you have exclusively Apple software on the iPhone then 'fast App-switching' does not impact your battery life.
However, as soon as you install third-party software that utilizes some of the APIs provided by Apple you CAN ABSOLUTELY see battery life impacted. This can happen for two reasons:
1) You are giving Pandora/Skype permission to trade battery performance for backgrounding API. After a call, Skype must be removed from the 'fast App-switching' panel in order to close data packets in the background.
2) There still is bad code out there today. These are bad Apps that aren't closing until iOS makes them. It's for this reason that once a day I close all the Apps that aren't going to be used in the near future.*
*Confirmed by my good friend Kyle. He has five years experience as Apple Genius and his ongoing frustration is people coming in with complaints about battery life. Looking at their device he finds 40 Apps in the 'fast App-switching' panel. The chance that one or more are using APIs or behaving badly is EXTREMELY LIKELY.
oh yea I'm lazy...
work 90-100 hours a week means I use my free time (little I do have) with my wife and daughter.Your genius friend doesn't understand the background APIs.
There are only four things that can happen in the background:
-VOIP
-Audio
-Location
The latter two will display an icon in the menu bar.
The fourth thing, is ANY app - BUT they can only run for up to 10 minutes.
Other than that, an app cannot run in the background, it simply isn't technically possible.
Its a quick launch menu that restores the app from a dormant state.
None of those apps are actually running for more than a few minutes (if they use the task completion API).
It's useful to note, however, that if you have lots of non-Apple apps sitting in your "multitasking" bar, you are putting a strain on your memory as either a portion of the App or the entire App remains in memory when it's down there. So if you have 20+ non-Apple apps down there and are noticing battery life draining quicker, it's possible that your phone has to work harder with more limited resources.
I haven't tested this, but it seems to make sense in my head.
I haven't tested this, but it seems to make sense in my head.
It's useful to note, however, that if you have lots of non-Apple apps sitting in your "multitasking" bar, you are putting a strain on your memory as either a portion of the App or the entire App remains in memory when it's down there. So if you have 20+ non-Apple apps down there and are noticing battery life draining quicker, it's possible that your phone has to work harder with more limited resources.
I haven't tested this, but it seems to make sense in my head.
Free memory is wasted memory.
Used memory doesn't drain your battery.
Don't use the multitask bar as a quick launcher. Just use the springboard.
iOS handles all the background memory swapping VERY WELL.
Don't need to close background apps unless you need to force quit something.
Close/stop background GPS/streaming apps that you aren't using.
If you're battery life is low, it's something else.
I've heard mixed opinions on the memory swapping. But I agree with the above to the extend that you don't have too many non-Apple apps in your bar (over 20). Then you should go on an app closing rampage.
Agreed.
1. The apps in the Recently Used Apps list still consume a bit of memory and cause a low memory condition for applications that leads to performance issues.
2. Apps leave you in odd places if you don't remember to back out to the beginning or close via the Recently Used App list (changing a wifi setting for example)
3. Some apps get confused, like the Photos (camera roll). Because it is open it doesn't always recognize new photos taken until you close it via the Recently Used App list.
I want to turn it off multi-tasking until they get it sorted out. And even then I may not turn it on.
To everyone saying that having tasks running in multitasking has no effect on battery, I highly disagree. With Jailbreak + SBSettings, you can see what's actually running and how much free ram you have, and I'll frequently see that if left to it's own devices, plenty of apps will stay running taking up RAM indefinitely:
Phone and Mail run no matter what, but obviously you'd want the Phone app running always - Mail, I actually wish I could kill, but oh well ....
Photos, App Store, Safari, Settings, Maps, Compass (and maybe others) will all keep running if you run them.
3rd Party apps that will stay running include Camera+ and Facebook (from what I run), and Camera+ uses a HUGE amount of ram on my phone (150+MB?)
Even if the app is doing absolutely nothing in the background because it's prohibited by apple's API (I don't know this to be true just because apple says it is, but let's just give it the benefit of the doubt here) -- refreshing 150MB of data takes energy, and the phone's OS will also have to work harder to run your other apps when you are nearly out of memory, due to memory fragmentation, and reduced space for caching.
If there's one thing I really like about JailBreak, it's that I can see what's running on my phone, and can keep track to kill apps that I use once and will not go back into for a long time (eg, if I go into Settings to check my Usage statistics, I will immediately kill it afterwards. If I am using Safari and Messaging to go back and forth between the two, I'll let them both run, but when I'm done using one or the other, I'll kill it as well. Backgrounder works really well to take control of what's allowed to multitask, and the "Badge" icon lets you tell what's running much easier.
When I don't pay attention to what's running and just let whatever run, I'll notice that my battery drains easily twice as fast.
And I'll have to disagree with you. When the app states are saved to RAM the OS does no extra work. The RAM would be powered regardless of whether there was data being stored there or not. In fact by continually closing apps that background you are using MORE power. Each time you reopen them the OS has to load them again from the flash drive. which consumes more power, instead of just retrieving their paused state from RAM.
The only exception to this are certain apps that use multitasking API's, for example Skype. This drains my battery noticeably, presumably because it keeps a heartbeart signal running to listen for calls. But for apps that do not use any multitasking API's apart from fast-app switching they do not consume any power whatsoever.
You don't understand how modern OSes manage memory.
Windows Vista had a terrible reputation for hogging memory, but all it was doing is the same thing that Windows 7, Mac OS X and Linux do.
Microsoft didn't clearly distinguish between memory that was "Available" and "Free" (a mistake they rectified with Windows 7). People assume that when memory is in use, that's a bad thing.
The reality is that it's much better for your computer (a phone is no different) to keep things you have already accessed in RAM so that if you need to use them again those things don't have to be loaded from disk (the flash memory on an iPhone).
RAM should use the same amount of electricity no matter how much it is storing.
The memory management in iOS (like all of the OSes I mentioned earlier) will keep caching things in memory until the memory is full and it needs the space.
In short, memory usage really should not be used as any indicator of power consumption.
How many times on this website have people said the exact same thing? At this point, these people just choose not to believe it. I wouldn't bother with them anymore - now it's just funny imagining someone stressing about how much energy that extra 150 MB of RAM is consuming or opening up the multitasking tray and manually removing two dozen app icons from it every day.