Isn't this big news? x64 emulation is coming to Windows on ARM

[Nermal]

Assuming WoA is released for Apple Silicon (and don’t forget it‘s only for a Snapdragon processor right now)

It's only officially for Snapdragon, but people have managed to get it working on Broadcom (Raspberry Pi) chips too. It may be that the community makes unofficial builds that run in a VM before Microsoft does.

Of course, there are legal issues with running such a beast!

 

[Nermal]

If the ARM32 is on the "optional" list then perhaps they dropped them, but if not on the optional list then they'd have to keep them. [ ejecting the Thumb stuff is decent ejection of "old stuff probably never going to use". ] Architectural license means can add extra opcodes on top, but dropping stuff that is part of the standard would be a very dubious loophole for ARM to put into their licenses.

Stealing a quote from another forum:

The ARMv8 Architecture Reference Manual states that AArch32 support is optional (section D1.20.2, “Support for Exception levels and Execution states”). ARM have even released CPUs of their own which are AArch64-only (Cortex-A34, Neoverse E1).

If Arm's own designs are 64-bit only then Apple's likely allowed to do the same.

Source (in this case talking about porting a 32-bit OS to Apple hardware).

 

[jdb8167]

That is actually a good question. Does Apple Silicon even support 32-bit ARM? This didn't even cross my mind. If they don't, the possibility of Windows on Mac is suddenly looking much more bleak.

@Nermal if I read the Windows documentation correctly, they do use the 32-bit ARM subsystem.

This is what needs to be emphasized. I know computer architecture is difficult for most people. People are getting confused by whether or not you need 32-bit ARM to emulate 32-bit x86. You don't but it might make it easier. Unfortunately that isn't the relevant question.

The question is can an Apple Silicon CPU run Windows On ARM under a virtual machine. It depends on whether Apple included 32-bit ARM instructions in their microarchitecture. Apparently there are two levels to this. One is if ASi can run 32-bit ARM instructions natively. This probably doesn't matter because nothing will ever be compiled on an ASi Mac to do this. But the other level is running 32-bit ARM code under a 64-bit hypervisor (a virtual machine). If this is available on ASi then Windows On ARM should run just fine even if it uses 32-bit ARM in its Windows kernel and OS.

Using Windows On ARM in a macOS virtual machine is going to depend on whether or not Apple implemented 32-bit instructions that can run in a 64-bit hypervisor. Emulating 32-bit and 64-bit x86 applications is dependent on getting Windows On ARM running in a 64-bit hypervisor in the first place.

 

[jdb8167]

Someone on a Reddit thread claimed that the A11 series does not support AArch32 execution at any level. Wikipedia does not list A32 or T32 as supported in the A11 and beyond.

You can see this for yourself. Look at the A10X Wikipedia page and then at the A12X page.

Apple A10X
Apple A12X

If you look at the side bar under the image of the SoC, you can see that the A10X lists:

Instruction set	ARMv8.1‑A: A64, A32, T32

For the A12X:

Instruction set	A64 – ARMv8.3‑A

A32 is missing.

 

[panjandrum]

But in general, a 10X reduction in CPU speed is what to expect. If the users notice this is another question and depends on what they use their computer for. Games and media editing will run poorly in emulation.

There is a little bit about Apple's emulation speed in the article about the Surface Pro. https://www.forbes.com/sites/ewansp...dows-10-arm-macos-apple-macbook/#40abd6e64c5f Sounds like performance under emulation will be adequate for most basic tasks (but no, not games or media editing). Apparently benchmarking software running on the A12Z is returning results just slightly slower than the current baseline i3 MacBook Air. That's a slow dual-core machine by today's standards, but I just rolled out a few of them at my school for testing and in terms of everyday functions (browsing, Pages, Keynote, etc) they are very speedy and perform quite well. So that's good news.

I do think much of the discussion here is confusing virtualization with emulation. Shouldn't matter what the hardware or OS supports directly - that's the job of the emulator. This is how you can run old console games on your PC, for example, even though the PC has absolutely zero hardware or software compatibility with the console in question. As mentioned, it's a huge freaking resource hog, so performance can really suffer, but if the underlying architecture is good enough, and the demands light enough, it can work. And it can provide absolutely critical compatibility. When Apple transitioned from PPC to Intel, for example, my MacPro 1,1 ran my PPC software just as fast under emulation as my dual 450 G4 Tower. But it took 4x2.66GHz cores to emulate the same performance as 2x450GHz cores. Slightly greater than a 10X performance reduction if comparing straight clock-rates, but that's not really an accurate comparison. So the performance was adequate. Not up to what you would have seen on a G5 machine of course, but plenty fast enough for the majority of products to work just fine.

Maybe there is something critical I'm not understanding here, but as long as the emulator itself is 64bit then whatever goes on inside it should be fine.

 

[jdb8167]

Maybe there is something critical I'm not understanding here, but as long as the emulator itself is 64bit then whatever goes on inside it should be fine.

What you may be missing is that it isn’t Apple creating the emulator but Microsoft and its emulator runs on Windows On ARM (WoA). The only way for Apple Silicon to run WoA is in a virtual machine. The question is whether or not that will be even possible depending on what part of the ARM instruction set architecture Apple implemented in the Apple Designed Silicon.

 

[leman]

Maybe there is something critical I'm not understanding here, but as long as the emulator itself is 64bit then whatever goes on inside it should be fine.

Thats exactly the problem — the emulator relies on the CPU being able to execute the 32-bit (Aarch32) instruction set. It seems that Apple CPUs don't have this capability at all.

 

[thingstoponder]

Thats exactly the problem — the emulator relies on the CPU being able to execute the 32-bit (Aarch32) instruction set. It seems that Apple CPUs don't have this capability at all.

Is there any evidence this is the case?

There’s a guy in this reddit thread saying it doesn’t and would actually run faster on 64 bit. I hope they’re right.

https://www.reddit.com/r/hardware/comments/j16j4f

 

[leman]

Is there any evidence this is the case?

There’s a guy in this reddit thread saying it doesn’t and would actually run faster on 64 bit. I hope they’re right.

Windows docs for ARM version seem to suggest that it needs Aarch32 support to run 32-but apps, emulated or not. At least that’s how I read it

Windows on Arm documentation

Learn more about running Windows on PCs powered by Arm processors. Find guidance on how to build Windows apps for Arm64 devices or iteratively update your existing Windows app to take advantage of Arm64 native capabilities.

docs.microsoft.com

 

[Altherekho]

Yes it is...Windows on Arm...as you know also written here https://www.theverge.com/2020/9/30/21495510/microsoft-windows-on-arm-x64-app-emulation , what you think ? Parallels?The meta os? Windows on Mac store ? ?Windows as app on iPhone 12 pro max? I mean Nvidia buys Arm and Apple said thunderbolt 4 will be in the silicon, not to mention Netflix with 4k on T2 only Macs, I’m going wild. I know but isn’t this an Armocalypse?Well ii want to believe !

 

[Altherekho]

What you may be missing is that it isn’t Apple creating the emulator but Microsoft and its emulator runs on Windows On ARM (WoA). The only way for Apple Silicon to run WoA is in a virtual machine. The question is whether or not that will be even possible depending on what part of the ARM instruction set architecture Apple implemented in the Apple Designed Silicon.

Seeing Microsoft Office already on Apple Silicon I think Microsoft in working by a lot on make it work.

 

[Altherekho]

I saw this

microsoft office apps are already on Apple silicons and lynus as well , so with Proton you could game on Apple silicon Macs by means of Linux?

 

[deconstruct60]

I saw this

microsoft office apps are already on Apple silicons

Microsoft Access on macOS where?
MS SQL Sever on macOS where?

Don't believe the hype. Windows isn't going away any time soon.

 

[Waragainstsleep]

I actually think it will suit Apple in the long run if Windows runs in a VM only with no viability to play games. Some 32-bit apps might be an issue but chances are Parallels and VMWare can put a layer in to cover that which will be perfectly adequate for low-overhead apps. Not being able to edit media in Windows VMs on Mac probably not a hug issue given how spectacular the A1X chips are at handling video streams. (I run OBS on my 16" MBP at less than HD and the fans ramp up.)
Not being able to Boot Camp games will push devs to port them to run natively on Metal.

 

[Chompineer]

I actually think it will suit Apple in the long run if Windows runs in a VM only with no viability to play games. Some 32-bit apps might be an issue but chances are Parallels and VMWare can put a layer in to cover that which will be perfectly adequate for low-overhead apps. Not being able to edit media in Windows VMs on Mac probably not a hug issue given how spectacular the A1X chips are at handling video streams. (I run OBS on my 16" MBP at less than HD and the fans ramp up.)
Not being able to Boot Camp games will push devs to port them to run natively on Metal.

No it won't. The Mac marketshare is tiny. It will push devs to just stop caring about the piddly amount of Mac customers they may have had anyways. It won't be worth the money or time.

 

[leman]

No it won't. The Mac marketshare is tiny. It will push devs to just stop caring about the piddly amount of Mac customers they may have had anyways. It won't be worth the money or time.

At the same time Mac users are more likely to spend money on software. Mac market share might be tiny, but their share among premium computers is substantial.

That said, I’m not sure I agree with @Waragainstsleep here.It could really go either way. Depends how good Apple silicon is. If a new MacBook Aircan compete with mid-range gaming laptops, yes.

 

[playtech1]

At the same time Mac users are more likely to spend money on software. Mac market share might be tiny, but their share among premium computers is substantial.

That said, I’m not sure I agree with @Waragainstsleep here.It could really go either way. Depends how good Apple silicon is. If a new MacBook Aircan compete with mid-range gaming laptops, yes.

I think the success or otherwise of Macs for gaming depends on whether AS Macs have sufficiently decent GPUs and are an easy target for cross platform development through engines like Unity and Unrea or major publishers' proprietary engines. The Mac market hasn't been big enough (and mainstream Macs not powerful enough) to encourage AAA game ports to date and a market fragmented between x86 and AS seems potentially even less appealing in the short term.

This thread has convinced me that the hurdles around getting Windows on Arm to work and emulate x64 emulation performance are very high, so Windows gaming is not an alternative.

I am not hopeful for AS Mac gaming, but hope to be proved wrong!

 

[deconstruct60]

I actually think it will suit Apple in the long run if Windows runs in a VM only with no viability to play games.

Virtual Machines and games aren't necessarily mutually exclusive. There is 3-5 cloud gaming platforms spinning up and/or deployed now. (Google , Amazon , Microsoft , etc ) . They are all running on virtual machine foundations.
The notion that they don't work at all when there are thousands of folks using them doesn't hold much water.

Are the most extreme, hard core gamers going that way? No. But was Apple every going to get the particular subgroup anyway? No. Apple only has to skip off some folks to largely blunt any losses in number of Mac buyers. It is already a relatively very small subset of Mac users and if make it incrementally smaller the approximation creeps toward 0% of the market. (which doesn't matter much. )

There are two missing major ingredients. One is virtualization support in the GPUs. AMD and Nvidia GPU are incrementally getting that. (newer , higher end ones do. ). And need OS support for that driver stack. (Apple is in process of doing a major driver overhaul so that may be in forward motion also. GPU driver disruption may be last on kernel reformation transition, but something is coming. ) . If Apple's Hypervisor foundation can allocate a 'slice' of a GPU and present that to Vmware/Fusion to use instead of their "emulated GPUs" then that will be as big of a leap as when Intel/AMD started adding hardware virtualization to their CPUs and radically change the size and scope of the VM making business. But Apple has to do substantive work there. However, if Apple is going to "bet the farm" on virualiztaion they should be investing substantive effort in that area ( may take a couple of years to fully get going. ).


Apple went back to license more tech from Imagination Tech. Lots of rumors swirled around going back for ray tracing. However, Imagination Tech also has virtualization support IP also. The virtualization doesn't have the gamer tech porn press sizzle to it, but Apple is lagging behind all the other major implementors there.

Some 32-bit apps might be an issue but chances are Parallels and VMWare can put a layer in to cover that which will be perfectly adequate for low-overhead apps.

While not impossible, it is doubtful those two will get in the emulation business. Their products have drifted way too deep into being dependent upon hardware virtualization support to work well and fast. They never jumped on trying to take market share away from SheepShaver.

If Apple's SoCs don't have aarch32 support then Windows WOW will probably use some relatively bad performance emulators to tap dance around the problem. At one point WOW was running on Itanium

https://docs.microsoft.com/en-us/windows/win32/winprog64/wow64-implementation-details

If a substantive number of other ARM implementors are going to dump aarch32 also ( e.g., folks doing Neoverse N1 , V1 which Microsoft will probably pick up for use in Azure) then they'll probably put some kind of 'band-aid' in WOW.

Not being able to edit media in Windows VMs on Mac probably not a hug issue

Again if Apple's future hypervisor can present a virtualized hardware GPU slice to the app in the VM that probably would work reasonably fine for many workloads.

given how spectacular the A1X chips are at handling video streams. (I run OBS on my 16" MBP at less than HD and the fans ramp up.)
Not being able to Boot Camp games will push devs to port them to run natively on Metal.

Seems to be implicit assumption there that Mac market share is going to ramp dramatically up. That seems doubtful. The Mac's high profits and relatively very low "antitrust " exposure is a combination Apple probably doesn't want to mess up. If the software vendor was relying on customers to use Windows in a VM image then they really were not going Mac support in the first place. If they thought the market was too small for the effort before it will just be worse now.

Apple isn't going to 'miss' them either because the vendor wasn't trying to engage before anyway. Taking Macs into
being solidly and more explicitly even better Macs is not a Window/Linux developer recruitment campaign at all. Not even close. It is about building deeper synergies with the iOS/macOS developer community Apple' has already got and making that developer ecosystem healthier (and probably grow larger ).


Apple's hypervisor doing hardware virtualized GPU slices would help macOS images running in VM images also. (at least for recent macOS images. Running quite old and/or desupported macOS images probaby want a lowest common denomiator virtual GPU. Which VMWare and Parallels will probably keep around as a "backup" and for VM images that don't know anything about Apple's GPU and/or semi-custom 3rd party GPUs. )

 

[Mayo86]

I think the success or otherwise of Macs for gaming depends on whether AS Macs have sufficiently decent GPUs and are an easy target for cross platform development through engines like Unity and Unrea or major publishers' proprietary engines. The Mac market hasn't been big enough (and mainstream Macs not powerful enough) to encourage AAA game ports to date and a market fragmented between x86 and AS seems potentially even less appealing in the short term.

This thread has convinced me that the hurdles around getting Windows on Arm to work and emulate x64 emulation performance are very high, so Windows gaming is not an alternative.

I am not hopeful for AS Mac gaming, but hope to be proved wrong!

From what I’ve seen, the graphics performance in the A12Z in the DTK is more than capable already. You have Tomb Raider (first one in the trilogy) running at 4K with almost maxed out settings on a A12-based chip. The capability is there. The remaining questions are: is there a consumer base and are there developers willing to do the work to appease those consumers?

 

[MisterMe]

No it won't. The Mac marketshare is tiny. It will push devs to just stop caring about the piddly amount of Mac customers they may have had anyways. It won't be worth the money or time.

This is not how all markets work--especially not the market for luxury goods. In the minds of many Mac adherents and Mac detractors alike, Macs are luxury goods.

As for the general topic of gaming on the Mac, the lack of top notch games on the Mac cuts both ways. If you want to play these games, then up to now, you had to look elsewhere. The Mac was not an option. Despite being virtually shut out of this corner of the market, Apple is the highest valued corporation on Earth. I have no inside information, but my guess is that Apple will do what it can to reverse its fortunes in this arena. If it succeeds, then it will have found yet another audience that it can appeal to. If it fails, then it will likely remain the highest valued corporation on Earth.

Think about that for a minute.

 

[Waragainstsleep]

Virtual Machines and games aren't necessarily mutually exclusive. There is 3-5 cloud gaming platforms spinning up and/or deployed now. (Google , Amazon , Microsoft , etc ) . They are all running on virtual machine foundations.
The notion that they don't work at all when there are thousands of folks using them doesn't hold much water.

Oh I'm aware that running an x86 VM on x86 hardware with something like ESX is a massively different beast than running an x86 OS on top of another OS, especially when you are having to translate DirectX to OpenGL. I was thinking purely about the latter which seem likely to be the only option on AS Macs.

There are two missing major ingredients. One is virtualization support in the GPUs. AMD and Nvidia GPU are incrementally getting that. (newer , higher end ones do. ). And need OS support for that driver stack. (Apple is in process of doing a major driver overhaul so that may be in forward motion also. GPU driver disruption may be last on kernel reformation transition, but something is coming. ) . If Apple's Hypervisor foundation can allocate a 'slice' of a GPU and present that to Vmware/Fusion to use instead of their "emulated GPUs" then that will be as big of a leap as when Intel/AMD started adding hardware virtualization to their CPUs and radically change the size and scope of the VM making business. But Apple has to do substantive work there. However, if Apple is going to "bet the farm" on virualiztaion they should be investing substantive effort in that area ( may take a couple of years to fully get going. ).

Again if Apple's future hypervisor can present a virtualized hardware GPU slice to the app in the VM that probably would work reasonably fine for many workloads.

This is interesting and something I haven't seen discussed all that much. I'm assuming based on ability that the 8 GPU cores in the A12Z are all capable of doing a lot more work than the individual cores you see listed in the specs for an Nvidia card, where there are ~1500 or so of them?

Any idea how the integrated GPUs in Intel and AMD CPUs stack up in terms of core counts? I wonder how many GPU cores Apple can conceivably stack on a single chip. I was pondering the Mac Pro the other day and wondered if they would look to build PCI-E cards with their own GPUs on them for extra graphics horsepower but figured there might be issues with memory bandwidth or something. The idea of using such a card to allow a host Mac the ability to assign GPU cores to VMs is interesting. I do wonder if Apple plans to find a much wider than usual range of uses for the Mac Pro in particular when they transition it to Apple Silicon. Some kind of ESX competitor might be one useful task if they can stack it with A series CPU and GPU cores and distribute them efficiently among VMs.

While not impossible, it is doubtful those two will get in the emulation business. Their products have drifted way too deep into being dependent upon hardware virtualization support to work well and fast. They never jumped on trying to take market share away from SheepShaver.

I presume someone is translating between DirectX and OpenGL when running Virtual Windows. Is that not VMWare/Parallels using some kind of emulation layer?

Seems to be implicit assumption there that Mac market share is going to ramp dramatically up. That seems doubtful. The Mac's high profits and relatively very low "antitrust " exposure is a combination Apple probably doesn't want to mess up.

I know traditionally Apple has run a model where they use software and services to sell profitable hardware but there are signs that is shifting lately. They are making more and more from services these days and look how cheap the iPhone SE is for what it is. Very unlike Apple historically.

If they want to grow their services further, market share is the way to do it. I have a feeling the first AS Macs are going to be pretty damn good. I won't bet much against them pricing them upwards as a result, but I won't be shocked if they come in aggressively low and shock a good few people either.
A small, thin, light, sexy MacBook at $600 or so would sell like mad right now and be absolutely perfect for most users to work from home. Edu markets would love it too. And its not beyond Apple's ability to build such a machine that would still kick ass compared to most of its Intel or AMD based competition. In terms of performance and battery life. And style.

 

[Waragainstsleep]

No it won't. The Mac marketshare is tiny. It will push devs to just stop caring about the piddly amount of Mac customers they may have had anyways. It won't be worth the money or time.

You're forgetting the billion iOS users those games will also work for. Thats a 40%+ market share of mobile and and considerably more than 40% when it comes to what they spend on software and in-app purchases.

 

[CWallace]

I was pondering the Mac Pro the other day and wondered if they would look to build PCI-E cards with their own GPUs on them for extra graphics horsepower but figured there might be issues with memory bandwidth or something.

China Times has reported that Apple is working on a GPU codenamed "Lifuka" which will be built on TSMC's 5nm process and believed to first see use in the ASi iMac in 2021.

 

[leman]

There are two missing major ingredients. One is virtualization support in the GPUs. AMD and Nvidia GPU are incrementally getting that. (newer , higher end ones do. ). And need OS support for that driver stack. (Apple is in process of doing a major driver overhaul so that may be in forward motion also. GPU driver disruption may be last on kernel reformation transition, but something is coming. ) . If Apple's Hypervisor foundation can allocate a 'slice' of a GPU and present that to Vmware/Fusion to use instead of their "emulated GPUs" then that will be as big of a leap as when Intel/AMD started adding hardware virtualization to their CPUs and radically change the size and scope of the VM making business.

Virtualization support is great if we are talking about common hardware with readily available drivers. But Apple with their custom GPUs? Do you really think that they will take on the burden of writing and maintaining Windows DX12, Vulkan and OpenGL drivers just so that some users can play games in a virtual machine?

Much simpler to delegate that task to the developers of the VM software. And frankly, a decent implementation that "emulates" other APIs on top of Metal won't be that much worse. Modern rendering APIs are fairly similar to each other and one can translate core Vulkan or DX12 into Metal with little overhead (not necessarily the other way around, since Metal has a more flexible resource binding model).

At any rate, Apple's virtualization APIs have no signs of GPU virtualization, and given the challenge of the task and very questionable benefits, I doubt that we will ever see it.

Any idea how the integrated GPUs in Intel and AMD CPUs stack up in terms of core counts? I wonder how many GPU cores Apple can conceivably stack on a single chip.

Ugh, that is a terribly confusing topic since every company has it's own definition of what makes a "core". Most of the time, they are just counting theoretical maximal throughput of a multiply+add instruction on 32-bit floating point numbers. For example, latest Nvidia Ampere series (RTX 3080 and friends) is supposed to double the amount of CUDA cores agains the precious pascal, but in reality, the amount of cores per processing unit is exactly the same. It's just that a "core" GPU can — under certain circumstances — process two floating point operations per clock, where the old architecture could do only one floating point + one integer operation per clock. And anyway, using the same nomenclature, an 8-core Intel Skylake CPU would have 128 "compute units" (because it can theoretically do 16 operations per cycle per core).

When you look at the hardware, the numbers sound more reasonable (don't quote me on that, I might have made some mistakes here)

Nvidia RTX 3080: a 68-core parallel processor cluster (each processor having four 512-bit SIMD ALUs)
AMD 5700XT: a 40-core parallel processor cluster (each processor having two 1024-bit SIMD ALUs)
Apple A12Z: a 8 core parallel processor cluster (each processor having probably two 1024-bit SIMD ALUs, not 100% sure)

etc.

I presume someone is translating between DirectX and OpenGL when running Virtual Windows. Is that not VMWare/Parallels using some kind of emulation layer?

They have a custom Windows driver implementation that uses Metal to "translate" the commands to the host GPU.

 

[MiniApple]

fascinating thread, even if I don't get all technical stuff. Thanks! ?

Looking at all that ARM transition from the aspect of a average consumer who doesn't need or have a seperate work (laptop) / play (console).

Is it difficult/time consuming/expensive for Devs to create a basic video/music player, photo viewer/light editor (think iOS Photos or Microsoft Photo) that runs on ARM?

Also, what about the different web browsers (Chrome, Firefox, Safari and Edge) and their extensions?
is i(Pad)OS/MacOS Safari already compatible?