Does iphone3gs handles memory different from iPod Touch 4 or iPad 1?

Hi,

I’m testing my game on all iOS devices (but this problem is only for iPad1, iPhone3gs and iPod Touch 4). All of them with the same build, and all the devices with the same iOS version ( 5.1.1)

My problem is that the memory ram displayed by the activity monitor from instruments is different in all of them
iPod Touch 4 = 61 mbs
iPhone 3gs = 64
iPad 1 = 67 mbs

My question is… why? Is it normal?
If not… .what could possible be happening?

thank you!

Activity monitor from instruments ? You mean from XCode ? Or with the SystemInfo.systemMemorySize

First solution :It’s probably because this display the effective memory which is not in used at this moment. (it’s probably this one after some research)

Second solution : It’s because the memory in mobile device is common to graphics & system so maybe in those 3 device the memory allow for graphics are differents.