Does Android really need a task manager?

[Guest Vailo]

I have been reading all over the net about best apps, widgets and android functionality. And one of the things that people keep mentioning is that Android in reality does not need a task manager to kill apps and free RAM. Applications in background do not use any resources until called up on (well depends on the case, some of them process things in background). So hence my question; Does Android really need a task manager when the system it self manages tasks just fine? (Or does it?) Personaly have no problem having lots of apps lay in background as long as it doesn't consume allot of battery, besides unused RAM is wasted RAM.

Any thoughts or comments?

[Guest Roter_Flieger]

I really recommend to read the one and only source for Android internals: the official SDK documentation. There is a chapter that deals with the lifecycle of an Android application - click here.

When you read that then you will learn that the only part of an Android application that may run in the background is a service and a broadcast receiver.

Killing a broadcast receiver is pretty bad: suppose you receive an SMS message. Phone.apk will send a broadcast intent into the system, the broadcast receiver of Mms.apk will respond to it and fetch the SMS data from the phone subsystem. Wait, your taskmanager killed the broadcast receiver of Mms.apk? Too bad...

Now suppose you start the Music player. The screen with which you interact is called an Activity. An Activity is only alive when you see it on the screen. As soon as you switch to some other program, i.e. the Activity is not visible on the screen anymore, it will not use any resources any more. Okay, it is still present in memory but if Android runs low on memory, it will not hesitate to kick it out.

Music playback itself may continue even if the GUI of the player is not displayed on the screen. You can easily browse the web and listen to some MP3. The playback is done by a service, that runs in the background and here it is: the only application components that may run in the background and that can use up substantial amounts of CPU and memory are services. Since Android 2.0 however, you can display all running services and stop them if needed (Settings->Applications->Services).

So do you need a taskmanager? In my humble opinion, NO. And this opinion is shared by a lot of respected Android developers as well as Google itself.

[Guest phhusson]

I have been reading all over the net about best apps, widgets and android functionality. And one of the things that people keep mentioning is that Android in reality does not need a task manager to kill apps and free RAM. Applications in background do not use any resources until called up on (well depends on the case, some of them process things in background). So hence my question; Does Android really need a task manager when the system it self manages tasks just fine? (Or does it?) Personaly have no problem having lots of apps lay in background as long as it doesn't consume allot of battery, besides unused RAM is wasted RAM.

Any thoughts or comments?

As far as I can tell, it's mostly useless. Sometimes some app bugs so hard that you need to kill them, but that's it.

Also that is true for our devices that has "plenty" of free memory, I guess that on G1 which has only 100MB of available memory, they might need memory killer.

And anyway, there is already a "taskiller" in the kernel, called lowmemorykiller, it kills app according to some priorities when the available memory is too low.

[Guest akira.pwr]

So, we don't need it? I've seen that everytime i tap es task manager widget, memory don't grow, became less... I have phhroyo rom, do you think it's better to uninstall it?

[Guest pipajoja]

could be a stupid question, cause i'm not really into android system or even programming...

so what's the difference between a service and an activity? do we truly have multi-tasking?

cause it seems to me when i switch between tasks they just run from scratch instead of from where i left off

not sure though

[Guest malez]

As far as I can tell, it's mostly useless. Sometimes some app bugs so hard that you need to kill them, but that's it.

Also that is true for our devices that has "plenty" of free memory, I guess that on G1 which has only 100MB of available memory, they might need memory killer.

And anyway, there is already a "taskiller" in the kernel, called lowmemorykiller, it kills app according to some priorities when the available memory is too low.

If the memkiler is well configured, there is no need to kill a task manuall, expect wit buged aps, as you said.

Many users don't know what thing implies : The want to have a max of free space but won't use it (because of a too aggressive memkiller) or the want to move apps to sdcard and have an empty data parition and won't use it at all.

For me there is no need of such application (Under Linux, we never use such application, sometimes we need a kill. That is the same under android that is a linux)

[Guest Squide]

in my opinion and the actual experience of using a task killer..

if you kill the task before the system terminate them when the memory is too low..

the system is a bit more responsive.

[Guest Vailo]

Many informative answers. I used to use task killers on my Windows mobile devices and now the habit has gone over to Android where I used to kill apps. But recently I have started to interest more in Linux and Android and have a little deeper understanding about how things work. So all in all Task killers are useless on Unix systems since the OS is smart enough to manage memory available.

[Guest navygino]

For memory, I think it is not really needed...

For me this is a power saving solution...

[Guest demolition23]

For memory, I think it is not really needed...

For me this is a power saving solution...

yea +1 for that

[Guest Vailo]

For memory, I think it is not really needed...

For me this is a power saving solution...

As I understand, RAM consumes insignificant amount of power, that's the reason I made this topic. There are no real gains killing background tasks, unless as malez and others mention above a app starts acting weird.

[Guest navygino]

As I understand, RAM consumes insignificant amount of power, that's the reason I made this topic. There are no real gains killing background tasks, unless as malez and others mention above a app starts acting weird.

I don't have figures...

But there is quite big difference in power consumption...

It allow my battery last longer.

[Guest jayziac]

Using 200 MB and using 50 MB consumes about the same power. The RAM chips are refreshed no matter if they store data or not. The only time when background processes suck up battery is if they continue to use CPU, GPS, or network resources.

[Guest Quipeace]

Using 200 MB and using 50 MB consumes about the same power. The RAM chips are refreshed no matter if they store data or not. The only time when background processes suck up battery is if they continue to use CPU, GPS, or network resources.

That's right, though it's more about poorly written apps that either refresh too much or keep running while the activity is in the background.

I personally gained much more by using 2G only, that saves loads of battery even if you don't use the data connection (I dont even have a plan sadly...)

EDIT: No I don't use a taskmanager anymore, Don't remember who said it, but unused ram is wasted ram.

Edited June 25, 2010 by Quipeace

[Guest Vailo]

I don't have figures...

But there is quite big difference in power consumption...

It allow my battery last longer.

I understand your logic, but as mentioned, RAM does not consume more power if there are more tasks loaded into it. As Quipeace have said, poorly writen widgets and apps can run processes in background and consume power by utilizing CPU, GPS, WiFi or some other chips in Liquid. I encourage you to try not using a task manager and let android handle things, I personally experience NO difference at all, my battery lasts as long as it did without the task manager.

[Guest Barleyman]

Ironically task managers are notorious for eating up your battery..! Seems everyone defaults to checking tasks/cpu/ram bazillion times a second like they'd do in linux/windows and eat up the power. After users complain it's (usually) toned down.

Another legitimate use for a task killer is to kill an obnoxious voip/messenger-style app that doesn't have "exit" functionality. Or just to restart an app which can't close itself.

[Guest Barleyman]

I understand your logic, but as mentioned, RAM does not consume more power if there are more tasks loaded into it. As Quipeace have said, poorly writen widgets and apps can run processes in background and consume power by utilizing CPU, GPS, WiFi or some other chips in Liquid. I encourage you to try not using a task manager and let android handle things, I personally experience NO difference at all, my battery lasts as long as it did without the task manager.

That's assuming the RAM is static. Accessing that RAM does eat up power and lots of it. So it'd be preferable to use apps that use less ram than more.

[Guest Quipeace]

That's assuming the RAM is static. Accessing that RAM does eat up power and lots of it. So it'd be preferable to use apps that use less ram than more.

Apps actually shouldn't do anything while sleeping (you can choose to let it do something but I really can't see why, use services if you need something done). So the memory that specific application is using won't be touched, or very little of it. (read the lifetime of an application if you want to know more about that)

Really, a taskmanager isn't nessesary. Take the following scenario:

Running:

Browser

Music

Now you're going to try and launch a game, but you don't have enough free ram. In that case android will close the browser and launch the game, resulting in a -very small- delay, but also makes launching the browser after you're done with the game a little slower, because it has to be loaded in memory again.

Second scenario:

Running:

Browser

Music

Now you close the browser because you're listening to some music. Using the taskmanager consumes memory and cpu clocks to shut down the browser. You're done with the music and decide to check the forums, you have to restart the browser even though there was plenty of ram to keep it running in the first place.

I hope you see what I mean :lol:.

[Guest Auxx]

Task killers are NOT saving battery! They eat it! Because they wake up from time to time, cycle through tasks and initiate killing process as needed. These operations force your CPU to run at max speed eating battery.

To save battery stop using lame software and stop unneeded devices like wifi, 3g, gps and so on.

[Guest Down to earth Swede]

Yeah, I know every experts opinions when reading into how androids internal works is that task killers isn't needed.

But you can just try it out and see if the system actually feels faster and more responsive.

My experience using white killer (one of the best task killers) is that it is night and day between using one and not using one.

The system is really sluggish at times and it won't go away UNTIL I use the task killer and then it is instantly fast and responsive.

I guess the "experts" will tell me and you that I am imagining this thing that I can see with my own eyes (and feel it as I use the phone).

And I haven't experienced any other problems by using it either.

It costs nothing for you to at least try it out, if it doesn't do anything for you, fine, then just uninstall it!

I was also skeptical after reading posts like the answers you got here, but then I tried "White killer".

If these taks killers didn't do their job, they wouldn't be as massively popular, would they.

Well I guess the experts would call all of us stupid, that it is just an illusion and so on....

Is it the "experts" opinion or your own experience that you get by actually trying things out that you should trust?

It is up to you!

[Guest jayziac]

There was probably a badly written app that was taking up excessive cpu cycles in the background and your task killer stopped it. It's one of the rare cases where a task killer does help. Other solutions would be to uninstall the offending app, or ask the developer to fix it. The more apps one installs on android the more likely there will be apps that misbehave. Since installing an app that has services is the same as turning it on. There is no installing an app (with services) but not turning it on like in regular PCs. I prefer to uninstall or not install apps that I don't use.

Edited June 29, 2010 by jayziac

[Guest Barleyman]

Apps actually shouldn't do anything while sleeping (you can choose to let it do something but I really can't see why, use services if you need something done). So the memory that specific application is using won't be touched, or very little of it. (read the lifetime of an application if you want to know more about that)

I didn't talk about sleeping apps. Any app that grabs lots of memory is going to access it when you're actually using it => power drain. OK, technically you can grab memory and not use it but that'd be just daft. So better to prefer apps with smaller memory footprint. Of course it doesn't really matter if you access same memory area 10x versus accessing 10 memory areas 1x but on this time and age I doubt you find many people optimizing their code to that degree, except maybe virus writers..

[Guest three_pineapples]

I use a task killer even though everyone says not to use it. To me it makes the phone more responsive and it improves battery life.

Most of you are just considering memory usage. But if an app uses the CPU for some reason when it shouldn't it will drain the battery. Same with the GPS or background data.

You do however have to be careful not to kill important tasks like applications that give you notifications (sms, email, IM, maps/latitude alarm, etc). But there is no reason not to kill the 99c game you bought last week that is probably poorly coded.

[Guest Barleyman]

I just had titan backup hang on me, technically it got stuck to "an operation is already in process"-state indefinitely. Without taskkiller I'd have had to reboot the phone.

[Guest Quipeace]

I just had titan backup hang on me, technically it got stuck to "an operation is already in process"-state indefinitely. Without taskkiller I'd have had to reboot the phone.

It's useful to have one installed, ofcourse, but the ones that automatically kill tasks -do not- make the system faster.

The (quite intensive) application you're using at that moment might respons faster if there are less background tasks to work on, but like I explained before, once you're done with that apps like the market or other web connected apps for example have to start up again, retrieving data from the web and processing that data takes up quite alot of time. (Just try to start the market and you will see).

I personally use an application called "jkappswitch", you can bring it up by holding the search button and switch between apps easily and when necessary, kill one. I used to use a more traditional appkiller, but got really annoyed when I had a webpage open -that needed to stay open- and the killer closed it...

Use one if you want to, but the answer to the OP's question is, yes a task -manager- is very nice to have, but a task -killer- is something completely different and in my opinion not necessary.