Comment by crote
14 hours ago
The hard part is doing so without completely ruining the existing app ecosystem. Rosetta 2 is genuinely impressive.
14 hours ago
The hard part is doing so without completely ruining the existing app ecosystem. Rosetta 2 is genuinely impressive.
Exactly this! Rosetta + the whole app developer community who really quickly released builds for M chips (voluntary or forced, but it did happen).
I had the initial m1 air, and it was remarkable how useable it was. You'd expect all sorts of friction and issue but mostly things just worked (very fast). Even with some Rosetta overhead it was still fast compared to intel macs.
Rosetta 1 delivered 50-80% of the performance of native, during the PPC->Intel transition. It turns out, you can deliver not particularly impressive performance and still not ruin your app ecosystem, because developers have to either update to target your new platform, or leave your platform entirely.
You can also voluntarily cut off huge chunks of your own app ecosystem intentionally, by giving up 32bit support and requiring everything to be 64bit capable.
...because users have no other choice when only one vendor controls the both the hardware+software. They can either use the apps still available to them, or they can leave. And the cost of leaving for users is a lot higher.
Vs. FEX and Prism?
Yes. Apple put custom hardware support in the M series chips based on the needs of Rosetta 2. The x86_64 performance on Rosetta 2 was often higher at launch than the prior generation of Intel chips running those same binaries natively.
Microsoft and Qualcomm already knew the performance of x86 app emulation on windows was killing the ARM machine lineup, so Qualcomm was working on extensions to their chips and Microsoft on having Windows support them already, but ARM64EC and Prism didn't launch for two years after the M1 shipped.
FEX uses TSO on M series chips.