[klodolph]

> I don't think that Apple will completely get away from x86 for a long time. Attempting to emulate the x86 on an Arm would be terribly slow.

It's not you're emulating an entire operating system: the operating system (and many libraries) are native, but the application code is emulated. It's faster than you think, and Apple has already done it twice: once in 1994, and once in 2005 (exercise for the reader: try extrapolating).

Apple's applications would be 100% native long before the ARM version shipped. Some intensive tasks—text rendering, audio/video/image encoding and decoding, HTML layout, JavaScript—these would also be native on third-party apps, since you just have to write the right glue into the emulator. This would be a lot easier than the 2005 switch from PowerPC to x86, which involved emulating a system with 4x as many GPRs and the opposite endian: ARM has 2x the GPRs as x86-64.

Sure, a bunch of apps will see reduced performance. Some will break. But remember: Apple has only been on x86 for ten years. We had the same problems during the PowerPC->x86 transition: you had to wait about two years to get a version of Photoshop that ran on x86 + OS X.

I'm willing to bet that Apple has been testing OS X on ARM for years now.

[ksk]

>but the application code is emulated. It's faster than you think, and Apple has already done it twice: once in 1994, and once in 2005 (exercise for the reader: try extrapolating).

Well in PowerPC->x86 transition x86 was the faster chip. The emulation cost was discounted by some amount. If you go from x86->ARM, ARM is the slower chip, so there's never going to be _improvement_ in performance compared to x86. I don't see why you're equating the two.