Sami Fathi, writing for MacRumors on an API change spotted in the second developer beta of iOS 15:
Currently, apps are limited to the amount of RAM they can use, regardless of the amount available on the device. For example, despite the highest-end M1 iPad Pro featuring 16GB of RAM, on iPadOS 14, apps are limited to only use 5GB. 16GB of RAM is the highest amount of RAM ever offered in an iPhone or iPad, and the 5GB limitation means that apps aren’t able to utilize even half of what the iPad Pro has to offer.
In the second betas of iOS and iPadOS 15, released to developers yesterday, Apple is introducing a new entitlement that developers may request that will expose their apps to more memory. Apple says that this entitlement will inform the system that an app “may perform better by exceeding the default app memory limit.” Apple’s developer documentation doesn’t specify how much extra RAM an app may be exposed to and also says this is limited to “supported devices.”
I’ve rarely found myself in a scenario where my iPad Pro needed more than 5 GB of RAM, but I’m also not a professional user of apps such as video or graphic editors that may take advantage of more RAM. This is an entitlement that Apple will need to grant developers who request it, and I’m curious to see how many apps will receive it later this year (or if this option will convince more developers of pro apps to finally bring them to iPad). I find it fascinating – but not surprising at all – that Apple is introducing this possibility while they’re pushing adoption of multiwindow and modern multitasking in iPadOS 15.