objective c - How to find available memory in iPhone programmatically?

Question

I'd like to know how to find programmatically available memory in iPhone from Objective-C?

Answer 1

You can get physical memory with the following:

NSLog(@"physical memory: %d", [NSProcessInfo processInfo].physicalMemory);

Available memory is going to be not something you can nail down to a hard number, since the os will kill off background apps for you as needed to give the foreground app more memory, along with clearing file caches etc. Assuming you're doing this to optimize your own caching, you could build your cache size based on physical memory and guess how much you should use. For instance, on an old 128m iphone 3g, your entire app would only get maybe 10-15megs of ram before it got killed, where a brand new 1024meg iphone5 is going to allow you hundreds of megabytes of ram before the os decides to kill you.

See memory in devices at http://en.wikipedia.org/wiki/List_of_iOS_devices