Opera Mini fans

One way to find out more details on the size of available flash and heap memory is to install and run an especial Java midlet. Here I introduce Java midlet called TastePhone, which is designed for testing the features of cell phones.

What you need is to visit at http://wap.club-java.com/en using your built-in browser and install the midlet into your phone. TastePhone test has two main phases. First in the basic test you start the midlet and select the language. Then you need to start the actual test by following the instructions. During the basic test TastePhone closes it's interface for five seconds and continues after that. When the basic test is done, you get page full of information about the phone specifications. Scroll down to section where you see 'Memory detail'. There you will see for eample imformation like this:

Total RAM size (heap): 1024kB = 1.0MB
Free RAM size at startup: 942kB
Free flash (RecordStore) size: 1508367kB = 1473.0MB

The second phase of TastePhone test is so called 'Optional test'. If you decide to run this, you will first see options for testing bluetooth, 3D graphincs and real maximum RAM. Deselect the first two options and continue for the real maximum RAM. Prepare yourself for a long wait. It may take even half a minute before nothing happens. After wait is over, Tastephone try to connect Internet and send the test results to TastePhone dataphase. You can deny this but by sending the information you help others to see what this phone model is capable of. Ask yes or no to these questions, just as you like, and you will finally see the final results, which looks something like this:

Total RAM size (heap): 3711kB = 3.6MB
Maximum size allocated before RAM full: 3501kB
Free RAM size at startup: 942kB
Free flash (RecordStore) size: 1508367kB = 1473.0MB

Additional test suddenly claims there's more RAM available. The total amount of RAM is 3.6MB and there are 1.5GB record store, which in this case is so large because there's external flash card in use. But what does that mean? To understand that we need to run some more serious tests. If we take a look at TastePhone test result again we will see another interesting information:

Advanced functionalities:
Can the midlet pause itself and stay active in the background: Yes/No

If yes, then it's possible to do the following. Close the TastePhone, start Opera Mini, browse a little and pause the midlet. In Sony Ericsson phones pausing can be done by pressing so called return key for a while. You get the options to either close the midlet or minimize it. If you minimize, then you just allow the midlet to run in the background. Now you can also run other midlets or phone tasks if you like. If you run TastePhone while OM is running in the background, you may get very different results:

Total RAM size (heap): 1279 = 1.2MB
Free RAM size at startup: 237kB
Free flash (RecordStore) size: 1508367kB = 1473.0MB

Total RAM size (heap): 2047kB = 1.9MB
Maximum size allocated before RAM full: 962kB
Free RAM size at startup: 237kB
Free flash (RecordStore) size: 1508367kB = 1473.0MB

And if you go back to Opera Mini, browse even more, and then run the TastePhone while OM is still running in the background, you probably get even more confucing results. You may even end up in to situation when TastePhone refuse to open because there's no free memory to run it. But what does all this mean? The answer is not very simple.

Especially on many advanced Sony Ericsson phones there's so called 'dynamic memory' used. Therefore the basic test gives very different values depending on what midlets are running and how much memory these midlets claim for themselves. But there is a limit how much space the midlets claim and how much the phone gives to them. For example on my Sony Ericsson K800i Opera Mini goes aproximately up to 1MB before it decide to clear the cache and start all over. And the total amount of memory all midlets can use is somewhere around 1.2MB.

When OM's cache is nearly full, and taking the size of OM midlet into account, the whole available memory is in use. At that moment it is also impossible to start any other midlets.

But why can't I get the total amount of RAM mentioned in the optional test into use? This is because phone needs to reserve some memory to other than midlet tasks as well. Built-in browser, phone calls and camera need their share of memory as well. In some phones, using less advanced memory structure, the midlets get just killed when you receive a phone call. The conclusion is that midlets are not necessarily allowed to use the all available memory.

Update 18 Nov 2009: Thanks to Selurus for pointing out A detailed comparison of Series 60 (S60) Symbian smartphones.