Does anyone know if its possible to set the amount of memory available in the simulator?
I'm assuming the simulator will use as much memory as possible from the system but this makes it more difficult to recreate certain low memory crashes/bugs.
No it isn't possible.
Testing things like memory consumption and performance should be done on the device, not the simulator. Even if you could limit the memory in the simulator you wouldn't get the same effect as there are very many different factors that will dictate how much available memory any given iPhone device will currently have.
You can simulate a "memory warning" to test if your responses to that warning behave correctly, but other than that, you should really be testing this kind of thing on a physical device.
You can invoke the "Simulate Memory Warning" in Simulator. Go to the "Hardware" pulldown menu. That's really about as far as you can go.
Apple documentation states that you can only simulate the low memory warning.
Having said that, there are limitations when invoking from the menu. Here's a post that lets you better simulate real world scenarios when trying to invoke the warning: Easier low memory warning simulator testing with keyboard shortcuts
I agree with @Jasarien that trying to limit the memory within the simulator is an artificial test and should be done on the device.
No this is not possible.
You can always simulate the memory warning situation. According to this you can also verify with the profiler how much memory your app is using see what limits you exceed.
来源：https://stackoverflow.com/questions/2545847/is-there-a-way-to-set-the-amount-of-memory-available-in-the-iphone-simulator