Rosetta Won't Support x86 Virtualization Apps Running Windows

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Apr 12, 2001
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Apple yesterday announced plans to build future Macs with its own custom silicon chips, and to ease the transition away from Intel processors, Apple revived the "Rosetta" feature that allowed PowerPC apps to run on Intel processors during the PowerPC to Intel transition.


Now revived, Rosetta will allow users to run apps that contain x86_64 instructions on Apple silicon, which means Intel-based apps will continue to work on Macs using custom Apple chips.

Rosetta is meant to provide developers with time to create native versions of apps, and there are a few limitations that are worth noting. As outlined in developer documentation shared this week, while Rosetta will be able to translate most Intel-based apps, it will not work with Virtual Machine apps that virtualize x86_64 computer platforms.

That means Apple's future Macs with Apple-designed chips will not natively support running current versions of software like VMWare or Parallels to run x86 Windows within the virtualization software. Other native solutions may appear, but will require efforts from 3rd party developers.

Right now, Macs have a Boot Camp feature that allows Windows to be run on them, but Apple has announced no similar feature for Macs equipped with Apple silicon. Kernel extensions also aren't able to be translated by Rosetta.
Rosetta can translate most Intel-based apps, including apps that contain just-in-time (JIT) compilers. However, Rosetta doesn't translate the following executables:

- Kernel extensions
- Virtual Machine apps that virtualize x86_64 computer platforms

Rosetta translates all x86_64 instructions, but it doesn't support the execution of some newer instruction sets and processor features, such as AVX, AVX2, and AVX512 vector instructions. If you include these newer instructions in your code, execute them only after verifying that they are available. For example, to determine if AVX512 vector instructions are available, use the sysctlbyname function to check the hw.optional.avx512f attribute.
Along with Rosetta, Apple has launched a new Universal App Quick Start Program for developers, which provides "tools, resources, and support" for testing and optimizing universal apps for macOS Big Sur.

Developers can apply to participate in the program, which provides a Developer Transition Kit that looks similar to a Mac mini but is equipped with an A12Z Bionic chip from the iPad Pro as well as 16GB RAM and a 512GB SSD, among other features.

The DTK will allow developers to begin creating apps that work with both Intel chips and Apple silicon, while Rosetta will provide support during the transitionary period. Apple said it will introduce the first Mac with a custom chip in 2020, and that it would take two years to transition the entire Mac lineup to its own chips.

More information on Rosetta, how it works, and the exclusions can be found on Apple's developer website.

Article Link: Rosetta Won't Support x86 Virtualization Apps Running Windows
 
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anshuvorty

macrumors 65816
Sep 1, 2010
1,141
770
California, USA
Well...there you go! No Parallels support unless Parallels finds a way to create a native Apple Silicon-based app/ARM-based app that can then virtualize x86-64.

So, it looks like Windows support is officially going the way of the dodo folks! Be prepared for this if you are thinking about jumping into the Apple Silicon-based platform when these laptops and desktops roll out at years end!
 

SamRyouji

macrumors member
Jun 1, 2016
57
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No VMs and BootCamp on ARM-based Mac product lines. Okay then, I think I'll keep my Intel MacBook as long as possible just for the sake of my Parallels in it.
And when the time has come, I think it would be better to settle on iPad + Windows laptop combo to get the best of both world.
 

Chompineer

macrumors regular
Mar 31, 2020
130
335
Ontario
Well, I suppose I’ll buy an XPS or a Thinkpad X1 Extreme when my MBP 16 comes out of service.

That sucks. But there’s just no way any of the apps I need are going to be rewritten for ARM, most of them don’t even exist for MacOS, but I get by with Bootcamp or VMWare Fusion.

I know a lot of other fellow engineers of various types will feel my pain here.
 

iFan

macrumors member
Jan 3, 2007
63
184
I'd imagine that for 98% of users this isn't a problem but for 2% this presents a major dealbreaker. They will probably lose certain pro customers, but gain others if they are able to provide better or cheaper Macs. I think in the end it will be a net win but curious how it will effect large F500 deployments at places like IBM.
 

CalMin

macrumors 6502a
Nov 8, 2007
686
235
Ouch. Then again Apple has the telemetry and knows how few of us actually use Windows VMs and/or Bootcamp. We are a small bunch of vocal individuals, but the actual percentage of us in the community has to be quite low. And I'm not quitting MacOS over this. I have a cheapo Windows Laptop that will do just fine for the 3-4 time a year that I need to run Windows.
 

moabal

macrumors 6502
Jun 22, 2010
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919
Would ARM still work with something like Microsoft Remote Desktop to use Windows app on the Mac?

I know there is a difference between Remote Desktop and VM. Any explanation is appreciated.
 

chrfr

macrumors G3
Jul 11, 2009
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umm Didn't the Demo show them running Parallels with a Linux virtual machine? Wouldn't this mean that Parallels is already working on a version for the Apple Silicon that can virtualize X86_64 systems?
That demo was running an ARM version of Linux.
- - Post merged: - -

Would ARM still work with something like Microsoft Remote Desktop to use Windows app on the Mac?

I know there is a difference between Remote Desktop and VM. Any explanation is appreciated.
Remote Desktop is showing the screen of the Windows computer- it's not doing any actual processing on the guest computer. In fact, you can use Remote Desktop on an iPhone or iPad today.
 

ipponrg

macrumors 68000
Oct 15, 2008
1,954
1,526
Well, this kind of puts a wrinkle in developing cross platform.

We use Virtualbox with Windows images for windows development on Mac. I suppose PPC -> x86 -> ARM makes sense now. It's cyclic and now they want to make the choice more obvious for when you need to do windows development.
 

tubedogg

macrumors regular
Dec 18, 2003
196
77
Minnesota
That means Apple's future Macs with Apple-designed chips will not support running software like VMWare or Parallels to run Windows within the virtualization software.
No, that means that Apple's future Macs with Apple-designed chips will not support using Rosetta to run software like VMWare or Parallels to run Windows within the virtualization software. You have no way of knowing whether VMWare, Parallels, or others will create Apple silicon-compatible software to virtualize Windows or other x86 platforms.

Edit: And I sure as hell am not taking any odds against them doing so. They'd have to be nuts to leave all that money on the table.
 
Last edited:

moabal

macrumors 6502
Jun 22, 2010
347
919
That demo was running an ARM version of Linux.
- - Post merged: - -


Remote Desktop is showing the screen of the Windows computer- it's not doing any actual processing on the guest computer. In fact, you can use Remote Desktop on an iPhone or iPad today.
You are absolutely right (I am an idiot should have thought it through) as I use Microsoft Remote Desktop on my iPad Pro! Haha.

I wonder though once most developers are using ARM for their apps how long they will support Intel. Does anyone know how long companies supported PowerPC after the transition? Our office bought some 2019 iMacs and are wondering the longevity.
 

threesixty360

macrumors 6502
May 2, 2007
320
385
The power PC based G5 years back had an app called Virtual PC that emulated x86. It was dog slow but it did it!

i think a company like Parrallels could build something similar. And they could accelerate some pc apps by running them using Rosseta translations directly.

they could also make a windows x86 emulation faster by offloading GPU tasks from windows to macs GPU. Virtual PC back in the day had to emulate the GPU and everything which was hard.

I think it can be done but will probably run at half the speed of the present VM. Which might not be that bad really.Just takes a lot of work.
 

tubedogg

macrumors regular
Dec 18, 2003
196
77
Minnesota
You are absolutely right (I am an idiot should have thought it through) as I use Microsoft Remote Desktop on my iPad Pro! Haha.

I wonder though once most developers are using ARM for their apps how long they will support Intel. Does anyone know how long companies supported PowerPC after the transition? Our office bought some 2019 iMacs and are wondering the longevity.
There are (granted, almost solely indie-Mac-developer) companies still distributing universal PPC/x86 bundles. I would guess at least 3-4 years for larger companies, though.
 
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