[oroup]

Adding significant BOM cost, growing physical volume, reducing battery life, creating lots of complexity to get certain apps to run on one CPU or the other and the associated cache coherency issues? So that iOS developers can test their apps on a native CPU (But still plenty of differences like screen size, no cell radio, no GPS, accelerometers, etc) Seems dubious.

[ChuckNorris89]

All Macs already have an ARM chip inside them in the form of the T2 chip.

[jedieaston]

But that’s specifically for Secure Enclave work (disk encryption, biometric data). I don’t think they’d want to risk someone running arbitrary code there and breaking the sandbox. (The SEP is also separate from the A-series chip in the iPhone for a similar reason, IIRC).

[monocasa]

In addition to the secure enclave, they already have an A series core on there. That's what runs the touch bar.

There's a full XNU based OS on there called "BridgeOS" that's in the iOS/tvOS/watchOS family.

[jdub]

Open System Information → USB on a Mac with a T2 chip and check out all the stuff attached to it.

[mappu]

So do all AMD Ryzen CPUs in the form of TrustZone/PSP, usually a Cortex-A5. It's equally as user-inaccessible as the T2.

[seedless-sensat]

There are probably a dozen ARM chips, e.g. WiFi module, battery controller, touch bar, etc