Closed Apps still taking up Memory

[Abarth1200]

Hi everyone noticedt his after I installed the app called System which shows you running apps, disk procces, memory use and graphs it all out nicely.

I noticed while having the System app open and double clickeing the home button to bring up the recently opened list, when I close them one by one I can see my free memory increasing.

So does this mean that the apparently closed appe are still running and taking up memory space.

I also noticed that in the procces window that maps is constantly running along with the phone procces.

What gives?

 

[CheesePuff]

Right. Now when you are in an app (lets say Messages) and you hit the home screen, it is still running in the background since it has a feature called "Fast App Switching" so if you were to go back to the Messages app it would open instantly to where you last left off.

 

[bobr1952]

My understanding is that the os will use the memory taken up by those apps when it needs the memory.

 

[sammich]

recently opened list

It's actually a 'open application list/bar'. Understand now?

 

[Abarth1200]

@cheesepuff, thanks already knew this

@bobr1952, this sounds feasable, thank you.

So it wont drain my battery faster the more apps it has in this halt state.

 

[Googlyhead]

@cheesepuff, thanks already knew this

@bobr1952, this sounds feasable, thank you.

So it wont drain my battery faster the more apps it has in this halt state.

If there doing any backgrounding (eg. music, messaging), yes; if not, they're not using any extra CPU. I guess there could be slightly less battery drain due to the extra processing required to close them, and the obvious saving if you switch back into them again rather than relaunch.

 

[CheesePuff]

@cheesepuff, thanks already knew this

If you already knew that then why ask the question since that's the answer?

 

[outphase]

It's actually a 'open application list/bar'. Understand now?

Not everything is open

 

[Carniphage]

It's actually a 'open application list/bar'. Understand now?

It's actually just an App history bar. Nothing more.

The apps represented in the list might be in one of three states.

• actually running in some way
• frozen but still in memory
• completely quit.

C

 

[Carniphage]

I guess there could be slightly less battery drain due to the extra processing required to close them, and the obvious saving if you switch back into them again rather than relaunch.

When you leave any app - it must do a conventional save at that point anyway even if the app is going to be frozen in memory.

This way, if the app needs to be dumped out of memory, it has already saved its state.

C.

 

[admanimal]

So does this mean that the apparently closed appe are still running and taking up memory space.

There is a difference between running and using RAM. Background apps only do the latter (with the few allowed exceptions of GPS, audio, voip, and task completing). It takes virtually no extra power to keep RAM bits alive and in fact having stuff already in RAM not only makes it faster to load again, but uses less power to do so. The system will remove a backgrounded app from RAM if it needs the memory for a foreground app.

There needs to be a sticky thread explaining multitasking because this question comes up at least once a day.

 

[Ashin]

Free Memory is wasted Memory, iOS4 will free memory from frozen apps if you really did fill it up and it needed more

 

[jdong]

@cheesepuff, thanks already knew this

@bobr1952, this sounds feasable, thank you.

So it wont drain my battery faster the more apps it has in this halt state.

Actually, it might save you battery because re-opening a "frozen" app takes less work than re-loading the entire application from disk.

Fast-switching "backgrounded" apps do not use any CPU resources while in the background.

 

[PNutts]

I had a genius appointment today where I took my iPhone 4 in because sometimes photos I take don't display in the Camera Roll and sometimes the phone "stutters" (Angry birds fly jerky across the screen). The Genius ran the diagnostic that said I was running low on Application Memory. She recommended that I close the apps from the recently used app list when I'm done with them and turn off the phone once a day. So, yes, "closed" apps (apps in the recently used app list) can and do take up memory.

 

[MEJHarrison]

I had a genius appointment today where I took my iPhone 4 in because sometimes photos I take don't display in the Camera Roll and sometimes the phone "stutters" (Angry birds fly jerky across the screen). The Genius ran the diagnostic that said I was running low on Application Memory. She recommended that I close the apps from the recently used app list when I'm done with them and turn off the phone once a day. So, yes, "closed" apps (apps in the recently used app list) can and do take up memory.

There's been a couple times when I've run into this. It's like something is running out of control in the background and it's eating up all the CPU cycles. However I believe it to be a bug that will hopefully be addressed in a future update regardless of what the "Genius" says.