iOS memory allocation - how much memory can be used in an application?

Question

Does iOs use non-contiguous or contiguous allocation in memory management? suppose if user allocates more than 128 MB, Will the App be closed? or Memory will be managed by iOS as if user allocates memory and misses deallocate in Deallocate method? is it possible to use more than 120 MB in application using well-defined data structure allocation?

Answer 1

You can use memory < your device ram capacity

(e.g. you're using 40 Mb of RAM, and then allocating 80 Mb's more for some short computation). In this case iOS would kill your application immediately.¹

List of results found by users testing with this tool:

device: (crash amount/total amount/percentage of total)²

• iPad1: 127MB/256MB/49%
• iPad2: 275MB/512MB/53%
• iPad3: 645MB/1024MB/62%
• iPad4: 585MB/1024MB/57% (iOS 8.1)
• iPad Mini 1st Generation: 297MB/512MB/58%
• iPad Mini retina: 696MB/1024MB/68% (iOS 7.1)
• iPad Air: 697MB/1024MB/68%
• iPad Air 2: 1195MB/2048MB/58% (iOS 8.x)
• iPad Pro 12.9: 3064MB/3981MB/77% (iOS 9.3.2)
• iPad Pro 9.7": 1395MB/1971MB/71% (iOS 10.0.2 (14A456))
• iPod touch 4th gen: 130MB/256MB/51% (iOS 6.1.1)
• iPod touch 5th gen: 286MB/512MB/56% (iOS 7.0)
• iPhone4: 325MB/512MB/63%
• iPhone4S: 286MB/512MB/56%
• iPhone5: 645MB/1024MB/62%
• iPhone5S: 646MB/1024MB/63%
• iPhone6: 645MB/1024MB/62% (iOS 8.x)
• iPhone6+: 645MB/1024MB/62% (iOS 8.x)
• iPhone6s: 1396MB/2048MB/68% (iOS 9.2)
• iPhone6s+: 1195MB/2048MB/58% (theoretical, untested)
• iPhoneSE: 1395MB/2048MB/69% (iOS 9.3)
• iPhone 6s+: 1392MB/2048MB/ 68% (iOS 10.2.1)
• iPhone 7+: 2040MB/3072MB/66% (iOS 10.2.1)
• iPhone X: 1392/2785/50% (iOS 11.2.1)

¹https://stackoverflow.com/a/5887783/5181636

²https://stackoverflow.com/a/15200855/5181636

More information can be found on this question.