High memory use after jailbreak...any apps available to monitor what's using how much

Who cares? The OS will free up memory when it needs it. Free memory is wasted memory.

 

Go to the app store and get an app named System. It will tell you running processes as well as free memory.

 

~80MB of free memory is plenty, you got nothing t worry about, if the system need more than that, it will free it up itself.

 

Does it slow the phone down at all whenever your ram gets low??

 

No, unless you reach 0 and that never happen, iOS is smart enough to free up memory when it needs to.

People freak out because they think of computer running out of memory and slowing down, this is because computer OS use Page memory (special partition on the hard drive), the hard drive is slower than RAM memory, iOS (and pretty much any mobile OS out there) does not work this way. In this case, Free memory is wasted memory. It doesn't consume more battery either which is another misconception, The memory have to be completely refresh all the time, so if you got 498MB free or 2MB free it will consume the same amount of current

 

That's true to a point. None of the operating systems out there function at their most efficient levels when free memory is quite low. Either they don't manage low memory conditions well or they spend a lot time and system resources managing the low memory environment. Neither is ideal. You don't need 300MB free on a 512MB system, but a bit more than zero free memory is a good thing.

S-

 

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its not a computer where if memory is not being released from a program, you can get over it since it usually happens only in situations where you're on the computer too long and use alot of resouces. You can restart the computer but its never that drastic

on a iphone on the other hand the OS is NOT smart enough to free ram, well it does, but guess HOW.......it CRASHES a app you're a using kicking you out of it.

to fix it you usually need to restart a the iphone which is time consuming and also affects battery power. Freeing ram using an app allows you to IMMEDIATELY give yourself the maximum ram available to you and you're on your way.

however yesterday I upgraded to 4.2.1 firmware and jailbroke it...I'm on low ram...ues to free up to 150mb now I gets 90mb sumthin, reception bars keep dropping and its abit sluggish. Stupid apple.

 

You say upgraded. Were you previously on iOS 3? iOS 4 is more resource demanding than iOS 3