The new M1-based 2021 Apple iPad Pro is no doubt a performance powerhouse. Aside from the M1 chip, the new iPad Pro also features 16 GB of onboard memory for the 1 TB and 2 TB storage models. However, not all of that RAM is available for apps as evidenced by a post by developer Lucky Clan, developer of the popular ArtStudio Pro app for the iPad.
According to Lucky Clan on the Procreate Folio forum, the 2021 iPad Pro with M1 allows developers to use only up to 5.1 GB of RAM for their apps. Allocating more than 5.1 GB results in the app crashing. This occurs on both the 8 GB and 16 GB iPad Pro 2021 models.
Hi, Artstudio Pro developer here.
There is a big problem with M1 iPad Pro. After making stress test and other tests on new M1 iPad Pro with 16GB or RAM, it turned out that app can use ONLY 5GB or RAM! If we allocate more, app crashes. It is only 0.5GB more that in old iPads with 6GB of RAM! I suppose it isn't better on iPad with 8GB. [sic]"
Developers of the iPad sketching app Procreate also indicated to a query on Twitter that "all M1 iPads have the same amount of RAM available..."
Last year's iPad Pro featured a maximum of 6 GB RAM with a maximum of 4.5 GB available for third-party apps, so apps aren't exactly constrained by the current 5 GB usage limit. iPadOS, though, can use all the memory to keep more apps running the background for a fluid user experience. However, the RAM limit does impede developers from taking full advantage of the 2021 iPad Pro; like limitations to the number of layers that can be used in photo editing, for example.
Initial reviews of the M1 iPad Pro indicated that the current iteration of iPadOS is a bottleneck in fully utilizing the M1's capabilities. That may change next month at Apple's Worldwide Developer Conference (WWDC) where the company is expected to unveil iOS 15, iPadOS 15, watchOS 8, macOS 12, and tvOS 15. Hopefully, iPadOS 15 can blur the line between the M1 Mac and the iPad Pro from a software standpoint.
As of now, all M1 iPads have the same amount of RAM available. If more becomes available in the future, we’ll make that available to you too ????
— Procreate (@Procreate) May 28, 2021