192
you are viewing a single comment's thread
view the rest of the comments
view the rest of the comments
this post was submitted on 11 Mar 2024
192 points (94.9% liked)
Technology
60070 readers
3249 users here now
This is a most excellent place for technology news and articles.
Our Rules
- Follow the lemmy.world rules.
- Only tech related content.
- Be excellent to each another!
- Mod approved content bots can post up to 10 articles per day.
- Threads asking for personal tech support may be deleted.
- Politics threads may be removed.
- No memes allowed as posts, OK to post as comments.
- Only approved bots from the list below, to ask if your bot can be added please contact us.
- Check for duplicates before posting, duplicates may be removed
Approved Bots
founded 2 years ago
MODERATORS
That’s one thing macOS does well: legacy support— at least for x64.
for now…
I have been running Windows 10+11 on arm for years now, the next version of Windows Server 2025 already has an arm preview release. Windows ARM has for a long time had x86 emulation, and has supported x64 emulation since about the start of COVID.
Is it actually emulation? Macs don't do that.
They convert the x86 code into native ARM code, then execute it. Recompiling the software takes a moment, and some CPU instructions don't have a good equivalent, but for the most part it works very well.
MacOS does use the term translations for its Rosetta Layer while Windows Arm uses the term emulation. I do believe the technical difference is that MacOS converts x64 code to arm64 on the fly, while part of the reason for emulation on Windows is to support x86 and other architectures. Someone more knowledgeable than me may be able to better compare the two offerings.
macOS converts x86 code to ARM ahead of launching an app, and then caches the translation. It adds a tiny delay to the first time you launch an x86 app on ARM. It also does on-the-fly translation if needed, for applications that do code generation at runtime (such as scripting languages with JIT compilers).
The biggest difference is that Apple has added support for an x86-like strong memory model to their ARM chips. ARM has a weak memory model. Translating code written for a strong memory model to run on a CPU with a weak memory model absolutely kills performance (see my other comment above for details).
They did a good job when moving from os9-osx. Adobe took a looong time to move to osx
I thought MacOS barely does any legacy support because apple isn't afraid to cut support for old stuff unlike Microsoft.