Regardless of how much RAM is available in a new M1 iPad Pro, no single app can currently use more than around 5GB because Apple has imposed a limit.
Even though the new M1-based iPad Pro comes with the maximum 16GB of RAM, Apple prevents an app from using all of it. In iPadOS, the maximum an app can use is about 5GB. As the developers of Procreate on Twitter revealed, this limitation limits performance. The image editing app Procreate has announcedthat it runs up to four times faster on the new 12.9-inch iPad Pro compared to the previous model but can only add about a quarter more layers to a canvas.
M1 iPad Pro with up to 16 GB RAM
Multiple layers put a strain on memory, and the new version of Procreate can reportedly handle up to 115 (compared to around 90 in the previous version). So the limit doesn't prevent apps from getting some performance improvement, but it does limit what they can do. Apple hasn't commented on the decision. However, the company regularly touts how fast the iPad Pro is at switching between apps. If a single app could use all of the available memory, that fast switching would be limited. The new iPad Pro comes in 1TB and 2TB versions, both with 16GB of memory.
iPadOS: Apple can raise the limit via update
Although no app can use more than about 5GB of RAM, having more available means more apps can be held in RAM and quick switching is possible without rebooting. The original 4GB version of the 12.9-inch iPad Pro from 2015 limited apps to 3GB under iOS 11.4. Similarly, the iPhone X under iOS 11.4 allowed apps up to 1.2GB. This increased to 1.8GB of RAM starting with iOS 12.1. That said, it cannot be ruled out that Apple will raise the limit in a future update. Consequently, this is not a technical issue. Rather, it is a long-standing decision imposed by Apple that is only now an issue now that the iPad Pro is equipped with significantly more RAM. (Image: Apple)
