Apple's Shifting Differentiation

Rosetta 2 allows you to run your x86 mac apps on Apple silicon. It's like the PPC->Intel switch again; your software keeps working regardless of the hardware underneath.

How is this going to work with games and GPUs?

It’s not without some overhead though, so there will be performance issues.

Fortunately those performance issues will probably only affect games released in a fairly narrow band of time, new enough that they’re still resource intensive but predating the transition. It would maybe be a 5 or 6 year span I guess depending on how performant the ARM system in question is?

Counterpoint: Try to run PPC software on a current mac.

“Keeps working regardless” is a great promise Apple has continued to make, but they only hold that up as long as it takes you to get the latest thing.

Nothing with Apple Silicon has a dedicated GPU, so, about the same. Existing calls to Vulkan and Metal don't need to be translated, the API and software stack are the same on the new hardware.

Dont think that's fair. PPC is very old. An extra 5 years of OS updates that support intel would be acceptable to me.

They've stated that some rosetta apps actually perform better on apple silicon due to the previous intel model being so slow (e.g. on the macbook air)

Meanwhile I can still use WindowsXP (and even DOS) apps on Windows 10, and many linux tools are rock solid without any ongoing maintenance.

Some problems are straightforward and have final solutions in software, and that should be seen as a good thing.

They plainly state that software with AVX, AVX256, AVX512, virtualization, and other nebulous instructions simply won't compile using Rosetta 2.

They seem to be attempting to avoid newer, patented instruction sets (Intel issued a strongly-worded statement about companies that attempt to use their ISA that seemed aimed squarely at Apple), but that means that SSE3+ (and maybe SSE2) are also avoided which could mean a lot more software doesn't work then they'd like to admit.

To add to parent’s point, AS is a one way trip to Big Sur, with no viable alternative (no downgrade, no dual boot anymore)

Then it’s not just big app companies that need to adapt, homebrew and CLI short lived utilities will also need ARM compatible versions or we’ll be wrapping each individual command in a Rosetta 2 launcher.

It might not be that bad, but I’d sure want to wait and see how it pans out, as it doesn’t look like a trivial transition.

"Keeps working regardless" for some period of time during the transition.

x86_64 Rosetta won't be forever, just like PPC Rosetta wasn't.

> and maybe SSE2

For x86-64, SSE2 came with the original x86-64 release in 1999/2000 (according to Wikipedia, it was announced in 1999 and the full specification became available in August 2000), so if patents are limited to 20 years, it's already out of patent.

Doesn't homebrew compile in place anyway? Macports does if they don't have a binary package handy. And as for arm compatibility, most command line tools come from Linux where they've already been compiled for arm ages ago.

So the CLI should be the least problem with Big Sur. Unless they somehow cripple it on purpose so you can't use common unix command line stuff any more.

Homebrew is fine, and nothing about the CLI is crippled in Big Sur.

No, they say AVX, AVX256, and AVX512 instructions won't work and to run them in conditionals that verify their availability.

More recent counterpoint: 32-bit x86 on a current MacOS.

Yeah that’s great. But macOS wouldn’t be the way it is if it didn’t make breaking changes over the years.

Windows 10 compatibility is an excellent achievement. But it comes at a cost of a significantly worse user experience (in my opinion, at least). Like legacy menu hell.

It should all work fine eventually, even if not on day 1 at least after a while. But I think there will be a transition phase for edge cases.

For ARM support for linux, my understanding is that pure server stuff is completely fine and battle tested, hobby/side peoject level utilities are a riskier bet. I remember hitting some of those on a rasberry pi a while ago, but then the situation might be way better already with all the buzz surroubding ARM nowadays.

For reference the github issue tracking page: https://github.com/Homebrew/brew/issues/7857

Aha yes, thank you

The Mach-O loader should transparently invoke Rosetta 2.

What’s a good thing is that different people can do things differently, according to their priorities.

Metal will be optimised. They said in the presentation that a game running on Rosetta would benefit from these optimisations, offsetting some of the slowdown resulting from the translation. So games that spend much of their time in Metal calls should be fine. Of course, the proof of the pudding is in the eating, which will start next week.