Hi, Tabs - What you are describing isn't exactly true. Free RAM does give you better performance - up until the point you run out of it. The Droid (and everything else out there with a CPU) will use RAM as applications/programs are run. And hopefully, very little RAM is being used to support the running programs.
And more importantly (and unfortunately more rarely), when an application is shut down, it will hopefully fully release every bit of RAM it used when the program was running. From what I have seen, applications are not releasing everything on the Droid.
If one program used every bit of RAM on your PC computer, that would be a very BAD thing, and your PC performance would severely suffer as a result. Why? Because at that point, the computer starts running in 'virtual memory' mode, where the computer starts utilizing hard drive space to act as a RAM replacement - and hard drives are hundreds of times slower to get data on/off than using RAM. Thus, any program (or the OS) that needs RAM at that point gets it from the much slower virtual memory.
This is why older PCs could still run WinXP when they only had 256 MB of RAM, even though WinXP would like to gobble up a lot more. Those PCs were mostly running from the hard drive virtual memory, which was obvious from slow performance and a hard drive light that was constantly 'On'.
Now, let's talk about the Droid. To my knowledge, once the Droid runs out of RAM, that it. End of story. I don't think it uses anything like virtual memory (and if it did, I pray it would
never use the SD card). Unfortunately, I've been watching the RAM usage on my Droid, and it constantly is creeping 'up', even when apps are terminated. That means that applications aren't releasing all of their memory. That also means that over time, the Droid will probably run out of RAM.
And once the Droid runs out of RAM, apps could start crashing. (I believe this is related to the 'Phone Call Echo' problem, but I'm not sure - but, the current solution is: 'Reset your phone') But, it looks like the Android OS is doing something about it. From what I have seen, there is some sort of RAM threshold level that once the Droid crosses over, the phone resets to clear up RAM usage. It's actually a pretty nice feature (if you're not in the middle of a call
). I have seen my Droid spontaneously reset a few times now. And I wouldn't have even known it occurred if I didn't see it happening.
So, yes - Knowing the amount of free RAM is very important, and although Android can shut down old apps to free up some memory for new apps, it doesn't guarantee that every byte of the memory from the closed app will be restored to the system. If you see free RAM disappearing at a fast rate, it usually means that a program was written poorly, and suffers from what is called in the industry as a 'memory leak'. Programs with severe memory leaks will cause computers (and phones) to crash or impact performance.