How to: Work that RAM - trying to multitask properly on S60 3rd Edition

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Recognising that we're stuck with a generation of S60 3rd Edition smartphones and communicators which are 'challenged' in terms of how much RAM is free for running its built-in applications, Steve Litchfield looks at exactly where the memory is going and offers some tips for improving performance.

You'll already have spotted my ruminations over RAM on AllAboutSymbian. Either Nokia were penny-pinching when they designed each of these devices, or there are technical reasons (power?) why so little RAM was included. Either way, we've got to learn to live with the situation.

Before going on, I should point out that low RAM should never stop applications running altogether, we're not talking about data loss here. On a Symbian OS-powered, multitasking device, the operating system simply closes other applications down in order to free up enough memory - the worst that usually happens is that the (hungry) program you're trying to run doesn't start - instead the OS asks other programs to close and then when you try again the original program starts up fine. All well and good, but it's a pain to have to keep re-opening basic PIM applications, for example.

E61 E70  N93  N80  N91

In preparing the table below, I was using the Nokia E70, in some ways one of the hardest hit by the lack of RAM because of the double-whammy hit of up to 6MB while the keyboard's open (i.e. with the landscape UI). What I wanted to establish was: which applications are safe to leave running most of the time and which are on the 'hit list' of apps to either avoid or use-and-then-exit?

In theory, you should be able to use any of the applications at the top of the table, leaving them running, then fire up a 'hit list' app, use it and then 'Exit' it again, with the original applications still in RAM and ready for instant use.

S60 3rd Edition Application Minimum RAM usage (including helper processes)
Calendar 0.2MB
Zip manager0.4MB
Handy Safe (3rd party secure, synced database)0.4MB
Clock 0.5MB
Notes 0.6MB
File manager0.9MB
Magi-Lines (3rd party strategy puzzle)1.2MB
Document (Eseries)1.5MB
Camera (on E70)1.5MB
WorldMate (3rd party time/weather/currency tool)1.8MB
Music Player1.9MB 
Sheet (Eseries)1.9MB
--- Everything below is probably on the 'Exit after using it' list! ----
Flash Player2.3MB
Mobipocket Reader (3rd party ebook reader)2.6MB
Camera (on N93)3.5MB
Wayfinder (3rd party sat-nav solution)5.5MB
Opera Mini (3rd party Java-based browser)7.7MB
Web7.5MB to 10MB, depending on the pages being viewed
Navicore (3rd party sat-nav solution)9.5MB

In practice, there are a few other things to take into account, of course. On the E70 you should basically avoid using any of the 'hit list' apps with the keyboard open. On the N93, you should allow for the fact that the Camera application is much more RAM hungry than that on other devices and probably deserves to also be on the hit list.

It's also worth noting that any J2ME games you download from your network operator will each require Java, just as Opera Mini did in the table above, so you're talking about a minimum of 6MB to run one of these. Watch out.

But, by and large, remembering the RAM hit of your installed applications and where they come in the table above should enable you to use your new smartphone more fully and not face the inconvenience of opening your Calendar again... and again... and again. Symbian OS (and thus S60) is fully multitasking - with a little thought about the programs you open you should be able to work the way you want to.

Steve Litchfield, August 2006

External link: Nokia E70 tips