Jan Zdarsa Multitasking was introduced in iOS 4, and since then many users have been wondering how to turn off multitasking so that they don't waste resources and the battery lasts as long as possible. But you don't have to turn off the apps, and in this article I'll explain why.
Multitasking in iOS 4 is not the same multitasking as you know from desktop or Windows Mobile. Someone can talk about limited multitasking, someone about the smart way of multitasking. Let's do it in order.
A new feature of iOS 4 is the so-called fast switching of applications (Fast Switching). If you click on the home button, the state of the application will be saved and when you return to the application, you will appear exactly where you left off before turning it off. But the application is not running in the background, only her state froze before shutting down.
The multitasking bar, activated by double-clicking the home button, is rather a bar of recently launched applications. None of these apps does not run in the background (with exceptions), there is no need to turn them off. If the iPhone runs out of RAM, iOS 4 will turn it off by itself. It is when switching between applications that you use the Fast Switching feature, because thanks to it you switch to another application relatively immediately.
In App Store updates, you will often find so-called iOS 4 compatibility. This often means building Fast Switching into the application. For a demonstration, I have prepared a video where you can see it the difference between an application with Fast Switching and without her. Note the switch back speed.
We have already explained that the bottom bar called by double-clicking the home button is not actually multitasking. But this does not mean that there is no multitasking in the new iOS 4 at all. There are several multitasking services in iOS 4.
- Background music – some apps, such as streaming radios, may run in the background. The overall application is not running in the background, but only the service - in this case, streaming audio playback.
- Voice-over-IP – a typical representative here will be Skype. This service allows you to receive calls although the application is not turned on. The activated application is signaled by the appearance of a new top bar with the name of the given application. Do not confuse this service with Instant Messaging, you will only be able to receive messages via push notifications.
- Background localization – a service using GPS can also run in the background. You can thus switch from navigation to e-mail, and navigation can continue to navigate you at least by voice. GPS can now run in the background.
- Completing the taskh – for example, if you are downloading the latest news from RSS, this task can be completed even after the application is closed. After jumping (downloading), however, the application no longer runs and cannot do anything else. This service only completes the split "task".
- Push notifications – we all already know them, applications can send us notifications about some event via the Internet. I probably don't need to go into it here anymore.
- Local notification – this is a new feature of iOS 4. Now you can set in some application that you want to be notified of an event at a certain time. The app doesn't need to be turned on, and you don't even need to be on the Internet, and iPhone will notify you.
Are you wondering what, for example, iOS 4 can't do? How is multitasking limited? For example, such an Instant Messaging program (ICQ) cannot run in the background – he would have to communicate and Apple won't allow him to do that. But there is a solution for these cases, for example, in that you use an application (e.g. Meebo) that remains connected even after it is turned off on the given developer's server, and if you receive a message, you are notified by a push notification.
This article was created as an overview of what multitasking in iOS 4 actually means. It was created because I saw confused users around me who kept opening the multitasking bar and closing applications immediately after using them. But this is nonsense and there is no need to do anything like that.
Steve Jobs said that he didn't want users to have to look into the task manager and deal with free resources all the time. Here the solution just works, this is Apple.
Thanks for the nice article.
I would just add that terminating the application can have one practical aspect - the application is actually reset. Specifically, the first version of IM+ for iOS4 had some kind of bug, and on the support page, as a temporary solution (before they release a new version), they just recommended closing and restarting the strangely behaving app.
It is certainly appropriate to use shutdown, for example, to reset the application, I completely agree!
Thanks for the article,
I would just like to point out that in order for applications to remain loaded in RAM and for fast app switching to work, battery power is needed, a little more than it needs in standby mode when the application is closed (let's not take memory leaks into account now) .
So, yes, this method is more battery-friendly, but the very fact that the RAM is filled with applications will cause a certain slightly higher battery load.
It would therefore be appropriate if Apple added the option not to let some applications run in RAM, the user would choose only those applications that he wants to leave in RAM, the others would be turned off, these are applications that, for example, the user turns on once in a while..
After all, the entire RAM is powered as a whole. Whether the bunch of bytes in it is a frozen application or free space is irrelevant. And what about memory fragmentation, etc... How would the memory chip know which part it should turn off and power on and which part it shouldn't? It's just stupid. The consumption of memory chips, if their content does not change, is also minimal today.
sorry, but my user experience says otherwise, the battery is, albeit slightly, loaded... and as someone writes below, the response of the 3GS also decreases, which will probably be better... nothing about that
It really shouldn't be that loaded, it's exactly as Adam writes. The memories should always be powered in the same way, and these dormant applications do not affect the processor.
As a matter of fact, I had and sometimes I have problems with the lower endurance of the iPhone 3gs when using applications that are not adapted for ios 4, but it keeps getting better and better, every day I slowly download a couple of updates... since the first wave of updates for iPhone applications arrived everything stabilized ;) and it's a fact that I also once had to perform a restore without even wanting to :)
I personally did not notice a higher battery consumption
I would like to point out that the more applications that are not turned off, the less memory and the slower the iPhone... in my case, the 3GS easily reaches 3 MB and is like a turtle....
When running out of memory, the iPhone shuts down running applications first, so it always has enough RAM. I don't notice any slowdown on my iPhone 3GS (and I'm a really heavy user).
my 3GS slows down excruciatingly… then it takes forever to open sms, calendar, etc… closing the par app helps a lot… (mostly Safari and omnifocus are enough…)
Unfortunately, I have to confirm, it is so.
I can confirm that - it is true. A 3GS with multiple running applications simply slows down. What I don't understand myself, but I really observe it on the phone.
4G has double the memory, so it will definitely be a lot better there...
I don't notice any slowdown either, I think the new OS is even faster than before, but that's probably just my subject. impression
I have 15 GB of applications in my iPhone, I use them and do not observe them. It's a fact that I had a similar problem and even wanted to go back to 4.0 GM, because it worked better for me... unfortunately, I don't have JB and I don't even have SHSH blobs saved, so that's impossible. I did a restore and everything started to work quickly and beautifully ;)
I've already seen a mention of local notifications somewhere, but I didn't find any option for it anywhere. E.g. updated Pocket Informant should have them, but ... I don't see. Somehow, I don't see notifications on my iPhone. I'm not satisfied, they seem insufficient.
And is it possible to turn off a sleeping application? Alternatively, how to quit an app when pressing Home automatically pushes it to the background?
It works - you hold your finger on one icon, then they all start shaking and a minus appears on them
According to my observation, iOS4 on 3Gs phone under heavy load turns a nice snappy modern phone into a rather unpleasant WM type smartphone (or PalmOS of my old Treo680) - it just lags, lags, lags. The only thing that helps is regularly cleaning running apps, and I really don't like that and I don't want to jailbreak - I'm seriously thinking about going back to iOS3, but I don't know what apps optimized for iOS4 would call it at the moment. I don't know, I'm probably an even bigger heavy user than the author of the article, but the applications that start slowly are unmissable - but I normally run - calendar, phone, sms, notes, things, 8 pages in safari, geocaching, photos, contacts, Bible, iPod and appstore ( 3MB of free RAM). I'm an Apple fan, but IMHO iOS4 is simply not suitable for older HW (including 3Gs).
bullshit. I have a 3GS with iOS 4 absolutely no problem. iOS 4 is for iOhone 4 and 3GS. The latter simply have a problem, which can freeze (as a 2G owner, I really understand) but it's logical. Either we want software development, and that will of course be a bit of a "state", or we want the hardware to be the same and we have to take into account that SF will not change too much.
The iPhone may have it handled well with multitasking, but unfortunately some apps don't. For example, COMIC READER MOBI simply informs me dryly that it will not load the next page because it is low on memory. I usually have to kill almost all the sleeping apps before it gets going again :-( And I have a 3GS and the above app is supposedly modified for OS4.
try to urge it with the application support, the problem is obviously there ;(
Can someone please explain to me where the local notifications are set? Is it in Settings > Notifications and do I have to allow it for certain apps? Otherwise, I didn't find any other notification settings (others are only in the e-mail collection settings, and I guess that's the push that sends the notification from the server) Thank you!
The application must support local notifications, for example an interesting application with local notifications is Notify 2...
Okay, but what about the Pocket Informant? It should be able to do that, but I didn't notice anywhere the difference between local notifications and others. I admit I haven't even tried it. They are trying Palringo in the premium version, something about notifications is written in the description (of course not about local ones), but I also don't have any badge on the icon. I can jump from the application to another place and then back again, but when I return, I log in again, which I didn't expect. If I am not directly in that Palring, there is no notification anywhere. It's alright? The worst thing is probably the 2Do application, which states that notifications only work under WiFi. Pretty pathetic for a task list, isn't it. For $7… a bummer. :-(
I still feel better with backgrounder than with apple's implementation of "multitasking". otherwise, I don't notice any slowdown of the 3GS, even with a full frame. at first I turned off the applications through sbsettings out of habit, later I gave up and it was fine
I did notice the slowdown on the 3GS, not every time, but occasionally. In any case, not all applications work correctly, for example TV Seznam from Seznam sometimes does not register the move to the active service and does not load TV program updates, so restarting the application will help, which is the opposite of the original state.
Hello community,
Has anyone ever dealt with an application complaint? with iOS4, navigation does not work for me and €89 is not at all small... how does the complaint process?
The problem is not in the application. Try restarting the iPhone, if that doesn't help, restore the entire phone. Navigon works fine for me on 3G with iOS4.
I don't notice the slowdown on the 3GS either, but where it bothers me is reloading open Safari windows. If there is enough RAM, the content of already loaded pages will be preserved.