Apple goes ARM

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Ramtop
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Apple goes ARM

Post by Ramtop »

Well, as long expected Apple are switching Macs from x86 to ARM:

https://arstechnica.com/gadgets/2020/06 ... rom-intel/

It's going to be interesting to see how much performance they can get from their ARM designs, and if it'll be competitive with x86 in machines like the Mac Pro.
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Re: Apple goes ARM

Post by roland »

RiscOS on my Mac in the future? 8)
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Re: Apple goes ARM

Post by SteveBagley »

roland wrote:
Mon Jun 22, 2020 9:24 pm
RiscOS on my Mac in the future? 8)
No chance I expect. As I understand it, Apple's silicon is likely to be AArch64 only, while RISC OS is stuck in AArch32 (32-bit) ARM land.

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Re: Apple goes ARM

Post by Naomasa298 »

Emulation layer?
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Re: Apple goes ARM

Post by Diminished »

Mmm. Saw this today.

I like the ARM architecture and feel a certain wistfulness towards it for obvious reasons, but I'm not convinced about performance. I suppose there are arguments to be made that most users who spend their time in a browser don't need bleeding-edge speed any more, that the Mac has never really been much of a gaming platform where such speed would be desirable, and that the proliferation of parallel algorithms reduces the need for single-threaded speed nowadays (especially with AMD in particular pushing 64-core systems), but I'm still a little sceptical.

Could well be that if I buy another Mac laptop, it will be slower on one core than the previous one I bought was -- but I'd love to be proven wrong.
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Re: Apple goes ARM

Post by Ramtop »

My suspicion is this has more to do with Apple having gaining control over a critical part of their designs then outright performance. I'd love to see ARM being competitive in raw speed with x86, but every attempt to do that has failed so far.

This move must have been in the works for several years, so one interesting factor is that the decision will have been made when Intel's performance plateau was starting to become obvious, but AMD was still stuck with the terrible Bulldozer architecture. In that landscape ARM probably looked like a solid choice, at least for laptops. I imagine lots of people would put up with a bit less performance for much improved battery life.

But AMD's new mobile parts are delivering circa 50% better efficiency than Intel, so Apple will have a much bigger hill to climb than they may have initially expected.
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Re: Apple goes ARM

Post by Naomasa298 »

Not one mention of Acorn in the BBC article about this. :(
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Re: Apple goes ARM

Post by scruss »

Ramtop wrote:
Tue Jun 23, 2020 1:33 pm
My suspicion is this has more to do with Apple having gaining control over a critical part of their designs then outright performance.
Yes, that one. Finally being able to unify iOS and MacOS. Lock down hardware the way that Apple wants. Third party apps? Maybe, in a suitably walled garden.
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Re: Apple goes ARM

Post by SteveBagley »

Diminished wrote:
Tue Jun 23, 2020 11:30 am
I like the ARM architecture and feel a certain wistfulness towards it for obvious reasons, but I'm not convinced about performance. I suppose there are arguments to be made that most users who spend their time in a browser don't need bleeding-edge speed any more, that the Mac has never really been much of a gaming platform where such speed would be desirable, and that the proliferation of parallel algorithms reduces the need for single-threaded speed nowadays (especially with AMD in particular pushing 64-core systems), but I'm still a little sceptical.
I don't think it is really wise to see it as ARM (well AArch64) vs x86-64 but rather how well designed the CPU architecture is (by the time the CPU is actually executing thing both ARM and x86 instructions have been split up into smaller chunks anyway) at providing ILP, cache performance, instruction reordering etc.That's why Apple designed ARM CPUs are outperforming ARM designed CPUs at the moment (and I suspect why they are referring to it as Apple Silicon and not ARM or AArch64, since it very much is their CPU design just using the ARM ISA)-- and why Intel CPUs are underperforming compared to AMD's Zen architecture.

The same will apply when it comes to Apple designed CPUs for the Mac compared to x86-64, has Apple managed to design their CPU well enough. It's also worth remembering that PA Semi originally started out designing Desktop CPUs. After all, every CPU Apple's designed to run in a thermally and power efficient environment, not in a desktop or laptop with space for decent cooling and battery.

What is certain though is that it is going to be very very interesting to see how this plays out -- particularly with Windows on ARM, and the companies like Nuvia, and Amazon targeting ARM at the server market. People in the CPU design sector are predicting the death of x86 in ten years…

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Re: Apple goes ARM

Post by anightin »

Talking about performance using the ARM Architecture... :)

https://www.top500.org/news/japan-captu ... rcomputer/
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Re: Apple goes ARM

Post by Diminished »

SteveBagley wrote:
Tue Jun 23, 2020 3:47 pm
People in the CPU design sector are predicting the death of x86 in ten years…

Steve
Well, I don't think I'd complain too much.

People with big Steam libraries might be a little peeved, though ...
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Re: Apple goes ARM

Post by Soruk »

Naomasa298 wrote:
Tue Jun 23, 2020 2:36 pm
Not one mention of Acorn in the BBC article about this. :(
How long before Apple's marketing engines start claiming these are the first ARM-powered desktop computers? If they do, well, Advertising Standards will be getting an email from me.
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Re: Apple goes ARM

Post by Richard Russell »

Ramtop wrote:
Mon Jun 22, 2020 9:03 pm
It's going to be interesting to see how much performance they can get from their ARM designs
Unless their CPUs have extended-precision floating point instructions - and as far as I'm aware no current aarch64 devices do - they simply won't be able to compete where high-accuracy numeric calculations are concerned. All x86 FPUs support 80-bit floats.
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Re: Apple goes ARM

Post by VectorEyes »

Soruk wrote:
Tue Jun 23, 2020 4:32 pm
Naomasa298 wrote:
Tue Jun 23, 2020 2:36 pm
Not one mention of Acorn in the BBC article about this. :(
How long before Apple's marketing engines start claiming these are the first ARM-powered desktop computers? If they do, well, Advertising Standards will be getting an email from me.
Pretty unlikely I think, they haven't mentioned ARM once publicly. It's 'Apple Silicon' all the way.
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Re: Apple goes ARM

Post by algenon_iii »

Naomasa298 wrote:
Tue Jun 23, 2020 2:36 pm
Not one mention of Acorn in the BBC article about this. :(
Let us be honest here, Acorn ceased to be last century, it's Cambridge-based ARM that carried on the legacy and developed the ARM architecture into what it is today.

To put it another way it's like saying a modern Windows 10 PC isn't being called and IBM PC Compatible, even though people have uploaded YouTube videos of a i7 or Ryzen PCs booting into MS-DOS 6. Talking of which you couldn't even run Arthur or an old version of RISC OS on a modern ARM CPU. Heck, I remember being miffed when old games I had wouldn't run on an A7000+ when I eventually got one.
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Re: Apple goes ARM

Post by algenon_iii »

Ramtop wrote:
Mon Jun 22, 2020 9:03 pm
Well, as long expected Apple are switching Macs from x86 to ARM:

https://arstechnica.com/gadgets/2020/06 ... rom-intel/

It's going to be interesting to see how much performance they can get from their ARM designs, and if it'll be competitive with x86 in machines like the Mac Pro.
In fairness, the article says
Apple's chip division has reached the point where it should be able to reliably compete with Intel on performance. The 2020 iPad Pro with an Apple A12Z SoC turns in comparable Geekbench numbers to a 2019 MacBook Pro with an Intel Core i9. An Apple SoC in a laptop, with a higher thermal budget, should do well, but Apple didn't offer any specifics yet
Which if true is very impressive :shock: . I don't see Intel going anywhere any time soon but recently AMD and now ARM-based processors have given them a run for their money. In my book that's a good thing as it makes sure companies keep innovating.
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Re: Apple goes ARM

Post by scruss »

Richard Russell wrote:
Tue Jun 23, 2020 7:30 pm
… they simply won't be able to compete where high-accuracy numeric calculations are concerned.
Curiously, all the recent effort in floating point are much lower precisions, like Bfloat16. ARM A64 supports this tiny float format.
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Re: Apple goes ARM

Post by Richard Russell »

scruss wrote:
Tue Jun 23, 2020 11:51 pm
Curiously, all the recent effort in floating point are much lower precisions, like Bfloat16.
Not so curious really,16-bit floats are useful for some video processing applications for example.

The precision of 80-bit floats is rarely required but the main reason for their existence (in all x86 FPUs) is to allow 'chained' calculations, involving many steps, to return an accurate 64-bit double result. Without them, each step in a complex calculation risks introducing up to 0.5 LSBs of error, which can accumulate to a significant loss of accuracy.

Interestingly, in the early ARM days when a floating-point coprocessor was envisaged (and emulated in software) all the common floating-point formats were supported: 32-bits, 64-bits, 80-bits. But when ARM CPUs eventually acquired integrated FPUs the 80-bit support was omitted; I don't know what the rationale was, other than to simplify the silicon.

More annoyingly still, if you compile a program which uses the long double type (80-bits on an x86) for an aarch64 CPU, most compilers will treat it as a 128-bit float, which has no support in the silicon on any current CPU and has to be emulated (slowly) in software. The exception is Apple compilers which instead treat it as a 64-bit float (synonymous with double).

If you want to see just what a difference 80-bits vs 64-bits can make, the BASIC program scarab.bbc (supplied as one of the examples with BBCSDL) is equisitely sensitive to the precision (64-bit top, 80-bit bottom):
scarab64.png
scarab80.png
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Re: Apple goes ARM

Post by mr-macrisc »

then Fujitsu ARM 40core processors are in worlds new top supercomputer as well.

The fact we could and are starting to see arm CPU’s in kinda desktop cpu/socket packages could be interesting and reckon it will give arm Linux a wee boost as they could slip in there as alternative OS for the new desktops (possibly/eventually) And proper desktop power to boot.
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Re: Apple goes ARM

Post by sa_scott »

Certainly interesting that it happens to be 30 years since Apple, Acorn and VLSI banded together to form ARM.

This article is certainly worth a read:

https://appleinsider.com/articles/20/06 ... le---twice
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Re: Apple goes ARM

Post by thecellartroll »

I'm just waiting for the first YouTube strip down of a new MacBook Pro revealing a Pi Zero and a kilo of hot snot :D
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Re: Apple goes ARM

Post by chinnyhill10 »

It's going to be a bit odd for us 'creatives" because the thought of a less powerful processor won't go down well when trying to shuttle around multiple 4k video streams. But I'm not sure Apple care about us any more.

I get why they want control though. Large power hungry hot running Intel chips vs ARM. It's the argument from the 1990's of ARM vs Intel all over again. Trouble is when you want to tow a heavy trailer up a steep hill you want a big dirty diesel not a sleek electric car. And I fear that as a person who needs 'grunt' I'll be faced with the horrors of Windows again (the only marginally good version they did was 2000/XP).
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Re: Apple goes ARM

Post by SteveBagley »

chinnyhill10 wrote:
Wed Jul 01, 2020 5:50 pm
It's going to be a bit odd for us 'creatives" because the thought of a less powerful processor won't go down well when trying to shuttle around multiple 4k video streams. But I'm not sure Apple care about us any more
Did you see the Final Cut Pro Demo at the keynote demoing exactly that? Manipulating three 4K video streams in real-time, on a two year old processor design aimed at the iPad? Or the photoshop demos? I think creatives will be fine… Grunt doesn’t come from the CPU instruction set architecture (x86 or Aarch64) but rather how the CPU implements that ISA — after all, once you get past the instruction decoder neither type of CPU is executing the instructions the programmer wrote, nor in the order they wrote them in but rather the simpler micro-ops that the instructions were decided too.

Until there’s genuine Apple Silicon Macs available (the DTK is a glorified iPad Pro after all) we have no idea how fast Apple Silicon Macs will run but its telling that both on the Desktop (Apple and Microsoft), in the server space (Amazon with AWS Gravitron, and the work Nuvia are doing) and supercomputing — there’s a move from x86 to Aarch64 CPUs.

Will x86 still exist in 2030? No idea, but it's no longer a silly question to ask…

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Re: Apple goes ARM

Post by chinnyhill10 »

SteveBagley wrote:
Wed Jul 01, 2020 6:32 pm
chinnyhill10 wrote:
Wed Jul 01, 2020 5:50 pm
It's going to be a bit odd for us 'creatives" because the thought of a less powerful processor won't go down well when trying to shuttle around multiple 4k video streams. But I'm not sure Apple care about us any more
Did you see the Final Cut Pro Demo at the keynote demoing exactly that? Manipulating three 4K video streams in real-time, on a two year old processor design aimed at the iPad? Or the photoshop demos? I think creatives will be fine… Grunt doesn’t come from the CPU instruction set architecture (x86 or Aarch64) but rather how the CPU implements that ISA — after all, once you get past the instruction decoder neither type of CPU is executing the instructions the programmer wrote, nor in the order they wrote them in but rather the simpler micro-ops that the instructions were decided too.
True but I'm skeptical about any Apple demo. Such tests are also very carefully chosen. I'm more interested in how an NLE will handle 4K video with lots of plug-ins running at the same time using camera codecs that are hard work to decode.

I haven't used Final Cut since it got dumbed down so am very much in the Adobe camp these days.

One thing they have done though is shot themselves in the foot over any immediate hardware purchases. There won't be any Apple kit upgraded here until the new kit is out and satisfactory. Who is going to lay down 2 grand on a laptop that will become obsolete very quickly? And who will make the jump to a platform where all their daily use software isn't running as well as it could as its still in 86 code? I remember running Office under Rosetta and that wasn't great. Interesting times
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Re: Apple goes ARM

Post by Coeus »

chinnyhill10 wrote:
Wed Jul 01, 2020 6:55 pm
...And who will make the jump to a platform where all their daily use software isn't running as well as it could as its still in 86 code? I remember running Office under Rosetta and that wasn't great. Interesting times
This reminds me that when Windows NT came out it was available for multiple processor types. Presumably, enough of it was written in a high level language that it could simply be recompiled with much less processor-specific assembler to maintain than had been the case with the previous bodges that were Windows on top of MS-DOS.

Despite that, there wasn't much software available for the other processors and eventually they gave up and went x86 only. yet Linux is available for very many processors and most of the software than runs on it is too. The difference, I suspect, is how it is delivered. The shrink-wrapped package doesn't make multiple versions easy - it's more inventory to hold, people will buy the wrong one and then return it, etc.

But what about the modern app store approach? If the software houses release their software compiled for the different processor architectures being used the app store can presumably download the right one for the hardware you actually have and should be able to seamlessly upgrade from a JIT emulated version to native as soon as the native one becomes available.
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Re: Apple goes ARM

Post by chinnyhill10 »

Coeus wrote:
Wed Jul 01, 2020 8:08 pm
But what about the modern app store approach? If the software houses release their software compiled for the different processor architectures being used the app store can presumably download the right one for the hardware you actually have and should be able to seamlessly upgrade from a JIT emulated version to native as soon as the native one becomes available.
What the new Macs need is a second processor port!
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Re: Apple goes ARM

Post by Ramtop »

Coeus wrote:
Wed Jul 01, 2020 8:08 pm
Despite that, there wasn't much software available for the other processors and eventually they gave up and went x86 only. yet Linux is available for very many processors and most of the software than runs on it is too. The difference, I suspect, is how it is delivered. The shrink-wrapped package doesn't make multiple versions easy - it's more inventory to hold, people will buy the wrong one and then return it, etc
This is, I think, the crucial difference. The vast majority of software run on Linux is open-source and available as source code, so supporting another processor architecture is not, in most cases, a big deal. But any OS with mostly closed source apps is, I suspect, always going to gravitate to one processor architecture and devs are not willing to ship and support multiple builds.

It'll be interesting to see how Rosetta 2 fares. My guess is it'll be an acceptable solution for Macbooks and iMacs because, to be blunt, nobody who cares about performance buys those. And Apple hasn't shown much interest in the Mac Pro line in recent years, so probably won't be devastated if people in that segment of the market go off and buy Threadripper Windows boxes.
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Re: Apple goes ARM

Post by chinnyhill10 »

Ramtop wrote:
Wed Jul 01, 2020 10:23 pm
It'll be interesting to see how Rosetta 2 fares. My guess is it'll be an acceptable solution for Macbooks and iMacs because, to be blunt, nobody who cares about performance buys those. And Apple hasn't shown much interest in the Mac Pro line in recent years, so probably won't be devastated if people in that segment of the market go off and buy Threadripper Windows boxes.
I'm sitting here on what was a top end iMac 2.5 years ago and it can hold it's own. As for the Mac Pro, they have only just launched the new cheesegrater models that have 28 cores. Although I just specced up the 'ultimate' model and it came out at 28 grand! And if you are laying out 28 grand you might have a few questions about OS roadmaps!

The graphics people, the video people, the music people all do care about performance. They must have something lined up to keep the range competitive unless they have totally lost the plot in the way computer companies always seem to eventually (Acorn, IBM, Commodore, Atari, Apple last time round, etc etc).
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Re: Apple goes ARM

Post by Ramtop »

I'm not sure it's Apple losing the plot so much as they don't much care about the high-end 'creator' market any more. They haven't been able to compete there for a long time; the trashcan Mac was lacklustre even when it was new and the cheesegrater is little better. Apple putting 28 core Xeons against the competition's 64-core Threadrippers was never going to end well, even without considering a Threadripper system will be quite a bit cheaper and will have none of the Mac Pro's annoying limitations, like the irreplaceable boot drive.

The iMac is better placed, if only because buyers are not quite as performance sensitive. I went and looked at Apples web site - the fastest 27" iMac that's available to buy has a six-core / six-thread i5 9600. That's a chip roughly on performance par with the low-end, budget Ryzen 3300X. And that's not even factoring in the iMac's slow RAM and 4-year old GPU.

So I suppose the lesson Apple has taken from this is that buyers who are looking for strong performance are already going to buy something else and that Macbook and most iMac buyers will keep buying so long as Macs continue to be fashionable sliver machines with MacOS and a fruit logo, even if performance falls even further behind. I suspect they're right, at least enough that the ARM switch won't hurt sales too much.
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Re: Apple goes ARM

Post by Elminster »

I expect they will just do the low end stuff and see how it goes.

I switched to Mac over 10 years ago, I had spent several years previously trying to make a Linux desktop work (I don’t like windows, but the rest of the world does). Linux desktops and applications have come a long way since, I am wondering if my 2 years old iMac when Apple no longer support it will be replaced with a Linux machine. My laptop is a Linux machine.

I have a lot of intel based paid for software and concerned that either I won’t be able to use it (without expensive upgrades) or it will be slow under emulation. I already lost most of the games I bought over the last 10 years when MacOS went 64bit only. Macs are not cheap, I don’t expect that to change, but I don’t want to pay a fortune for a machine that I can’t use half my software unless I pay another fortune.

It might be okay, maybe I am getting cynical, or it could be bad. After all Apple have done 68k to power pc to Intel so they should be able to make it easy. But what about the other 3rd party developers.
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