Allocation for app on iPad 1 is 4x that of iPad 2

Question

When I profile my app on an iPad 2, it loads with just under 1MB of allocated memory. When I do the same on an iPad 1, it loads with about 4MB allocated. Both are updated to the same iOS version. Is this normal behavior? If so, is there anything that I can do about it?

Answer 1

One possibility I would investigate is where the app is storing its resources. The iPad2 undoubtedly has more vram for textures, sound ram, etc. so it might be storing those resources on the hardware, while the iPad1 would have to store them in host memory and upload them as needed. A quick way to test this is to down-sample your resources and see if it has a bigger impact on iPad1 than on iPad2, if so then this is a plausible explanation.

For instance, if you have 8MB of graphics, and the iPad1 has 4MB vram available for textures while the iPad2 has 7MB available, then iPad1 will store 4MB of your textures in vram and leave the other 4MB in host ram, while the iPad2 will store 7MB of your textures in vram and leave the other 1MB in host ram.