[TUHS] PG3 or Gen3.0?

[Adam Thornton via TUHS]

The x86_64 emulation in Rosetta 2 is pretty good, although macOS 27 is
going to be the last one that includes it.  However...in general I'd say be
wary of x86_64-only applications.  At least at GCP (I don't know about AWS)
you get slightly more performance per dollar (well...better for integer,
worse for floating point, so it depends on your workload, but mine's mostly
integer) if you go with aarch64 even for Linux.

This isn't the first time an almost-hegemony got dethroned, of course.  We
had, at the beginning of my career (I'm kinda young for this crowd) "all
the world's a VAX".  After that, for a long time, x86 and amd64 came very
close to being the only architecture out there, but then Intel/AMD couldn't
keep up with the need for low-power devices (perhaps because their
instruction set had evolved so incrementally and with so much emphasis on
backwards-compatibility), and ARM basically entirely devoured the mobile
market, and seems to be coming for the server market as energy prices go
up.  Unix has been multiplatform since v6, and both GCC and LLVM support
many,many targets, so there's little excuse for single-architecture
applications.  If whatever you're running is x86-only and it's a Mac app,
then it's probably abandonware.  Which, I mean, fair enough for this crowd,
but also if it was written assuming 2015 hardware specs, it probably runs
just fine under emulation on a modern ARM system.

Generally, it's not that ARM is any faster than x86_64--but it can take
much less energy to give you the same amount of computation.  If you only
have a couple hundred watts of compute at home on things that are mostly
plugged in, you probably don't care, but if you're renting your capacity
from someone else, or trying to run on battery much, it starts to matter a
lot.

Apple has made an interesting choice in this space.  My M1 Macbook Air was
*astonishingly* better than any laptop I'd ever previously owned.  It
wasn't really any faster than what it replaced (an Intel Macbook Pro), but
it had a sixteen-hour battery life while still weighing less (the battery
is of course the majority of the weight of the machine).  The M3 I now
have, on the other hand, is just the boring standard incremental upgrade
over its predecessor.  A little faster, the screen's a slightly better
resolution, but it's not the "I can run for *how* long before I need to
plug into a socket?!?" that the M1 was.

Adam

On Fri, May 8, 2026 at 8:57 AM Cameron Míċeál Tyre via TUHS <tuhs at tuhs.org>
wrote:

> I've come to realize, only recently, that Apple moving from Intel's x86-64
> architecture to their own take on AArch64/ARM64 might help them streamline
> design, development and production but it's a royal pain in the derriere
> for many other reasons. Quite a few packages I've tried to install over the
> last year have turned out to be for Intel x86-64 Macs and nothing later.
>
> Regarding your issue, below, you can disable SIP, or at least, you used to
> be able to do so.
>
> Have a great rest of your day, everyone. The weekend starts at 5 pm...
>
>
>
> On Friday, May 8th, 2026 at 4:32 PM, Clem Cole via TUHS <tuhs at tuhs.org>
> wrote, in part:
>
> >  FWIW: I just ran into the shared library issue this week with macOS
> Tahoe
> > — some of Apple's binaries and dynamic libraries are compiled as arm64e
> > [which only Apple can certify — it part of the SIP system], so package
> > managers must use the traditional arm64; but try to mix certain programs
> > using exec that have shared libraries and SIP will fail.
> >
>