Analyzing Instruments readings

Question

Leaks:

None

ObjectAlloc:

Net Bytes: 4,332,512
# Net: 26,696
Overall Bytes: 103,769,552
# Overall: 738,987

Activity Monitor (MyApp):

# Thread: 6
Real Memory: 63.65 MB
Virtual Memory: 209.45 MB

Memory monitor showed same readings as Activity Monitor. I don't know whether these readings are good or bad. Memory indicated by Activity Monitor is horrifying. Should i be worried? Can i somehow estimate memory used by the application once its moved to the device. The real run time memory? Thanks.

Answer 1

Memory usage as reported by Object Allocation is not very autoritative, at least according to my experience. The real deal is the real memory consumption as reported by Memory Monitor, see my question on iPhone memory consumption. Your numbers seem to be measured in Simulator, such measurement is worthless. You have to measure on the device.

Answer 2

Object Alloc is reporting to the total memory used over the entire lifespan of the run. That means if objects are allocated and deallocated (which they often are) you see all the memory consumed in total.

Far more useful is to select the option "created and still living", then highlight regions of the graph where memory increases but it never goes down if you expect it would. Then you can see how much memory is being allocated at that point and what is allocating it. This works in the simulator as well as the device.