Hi all, fun topic. Five clarifications below:
First- Cletus, your Notes app test only tested the overall Notes application code architecture, not whether the Notes app or the underlying OS are specifically multithreaded.
Second- Multithreading has been available to iOS/iPadOS application developers for at least 12 years, since iOS 2.0 (released July 11, 2008):
See link:
Apple Developer Documentation on NSThread
Background info: multithreading is not processor-technology dependent. A processor with only 1 core can still run multithreaded apps. The operating system kernel manages which thread is active at any given time (with time measured in milliseconds) regardless of whether your CPU has 1 core or 48 cores (and regardless of how many CPUs your computer has).
Multithreading was first introduced in 1967:
See link:
Wikipedia entry on Threading
While symmetric multiprocessing (2 or more separate CPUs per computer) has also been around since the 1960s, multicore processors (one CPU with multiple cores) were not introduced until 2001:
See link:
Wikipedia entry on history of symmetric multiprocessing
See link:
IBM taking pride in inventing first CPU with multiple cores
My point: there is no improvement needed in modern Apple handheld hardware or software to better support multithreading. Multithreading has had 1st-class support since their introduction and the technology is decades old.
Third- regarding multitasking, there are two aspects to multitasking:
- whether the core operating system kernel supports it. iOS has supported and used multitasking at an operating system level since day 1 of the first iPhone and first iPad. iOS is built on the mach kernel which has supported multitasking since its inception, just like any Unix derivation has since the 1970s. To be clear, starting an App on the first iPhone or iPad did not suspend operating-system level tasks and processes. They continued to run, sharing processor time with the user's App, as you would expect with an operating system kernel that supports multitasking.
- whether the UI design allows multitasking at a user level. iOS enabled user-level multitasking in 2010 with version 4. The iPad picked it up a few months later. See link: iOS - Wikipedia
Fourth,- the general question of whether we will see "Apple Silicon"-compiled macOS apps on iPads: not without significant developer work in rewriting their apps to target and test the iPad as a platform for their app.
Background info: macOS apps historically have been built using an Application Programming Interface (API) called AppKit that Apple provides. AppKit is not available on the iPhone or iPad and never will be. For practical purposes it is deprecated and developers are being encouraged to transition to Catalyst or SwiftUI.
See link:
Apple Developer Documentation on AppKit
See link:
Apple Developer Documentation on Catalyst
See link:
Apple Developer Documentation on SwiftUI
Historically the iPhone/iPad have had a separate UI API called UIKit, which has never been available on macOS until Apple introduced Catalyst last year.
See link:
Apple Developer Documentation on UIKit
As mentioned above, nowadays macOS apps can be rewritten to use either Catalyst and SwiftUI as their UI API. However, once an app uses those APIs, it still can't just "run" on the iPad natively. These APIs don't imply the binary is universal. Developers must still re-target the iPad (if they want to) with a separate build and slightly different UI design (for example, the iPad does not have a menu bar and does not handle user files in the same way macOS does).
Finally, fifth: will we see Lightroom Classic for iPad? Likely not. LrC of course uses Adobe's own homegrown UI API to keep consistency across platforms. That's why it doesn't look like a macOS app. instead it looks almost exactly the same on Windows and Mac. But at some level in their code they have a platform-specific layer (to use the menubar, to use macOS open/save dialogs, to display
anything on the screen, etc), and I'd bet money on that layer relying on AppKit on the Mac, which is not available on the iPad.
So while an iPad LrC might
technically be possible down the road if Adobe invests significant resources in rewriting LrC's OS-specific UI layer in Catalyst or SwiftUI... why would they, when they have a first-class mobile app already on the iPad that is cloud-friendly, mobile-friendly, and synchronizes edits with Lightroom Classic if one wants it to? It makes no business sense.