this post was submitted on 11 Mar 2024
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Interesting. Samsung making a bold move here, but one that could make sense.

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[–] cmnybo@discuss.tchncs.de 48 points 8 months ago (5 children)

ARM is great on Linux where almost everything has an ARM version and apple can simply mandate that everyone supports it, but where are you going to find windows programs compiled for ARM?

[–] pelya@lemmy.world 22 points 8 months ago (2 children)

The only reason Windows is still relevant is a massive volume of legacy x86 applications.

If that laptop won't support x86 emulation, it'd be actually worse that Linux ARM laptop.

[–] gregorum@lemm.ee 8 points 8 months ago* (last edited 8 months ago) (3 children)

That’s one thing macOS does well: legacy support— at least for x64.

for now…

[–] Spiralvortexisalie@lemmy.world 12 points 8 months ago (1 children)

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.

[–] abhibeckert@lemmy.world 3 points 8 months ago* (last edited 8 months ago) (1 children)

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.

[–] Spiralvortexisalie@lemmy.world 4 points 8 months ago (1 children)

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.

[–] BorgDrone@lemmy.one 6 points 8 months ago

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).

[–] tsonfeir@lemm.ee 4 points 8 months ago

They did a good job when moving from os9-osx. Adobe took a looong time to move to osx

[–] Aasikki@sopuli.xyz 1 points 8 months ago

I thought MacOS barely does any legacy support because apple isn't afraid to cut support for old stuff unlike Microsoft.

[–] samus7070@programming.dev 5 points 8 months ago (1 children)

Any program written for the .net clr ought to just run out of the box. There’s also an x64 to ARM translation layer that works much like Apple’s Rosetta. It will run the binary through a translation and execute that. I have one of the windows arm dev units. It works relatively well except on some games from my limited experience.

[–] BorgDrone@lemmy.one 15 points 8 months ago (1 children)

Any program written for the .net clr ought to just run out of the box.

Both of them?

There’s also an x64 to ARM translation layer that works much like Apple’s Rosetta.

Except for the performance bit.

ARM processors use a weak memory model, whereas x86 use a strong memory model. Meaning that x86 guarantees actual order of writes to memory is the same as the order in which those writes executes, while ARM is allowed to re-order them.

Usually it doesn’t matter in which data is written to RAM, and allowing for re-ordering of writes can boost performance. When it does matter, a developer can insert a so-called memory barrier, this ensures all writes before the barrier are finished before the code continues.

However, since this is not necessary on x86 as all writes are ordered x86 code does not include these memory barrier instructions at the spots where write order actually matters. So when translating x86 code to ARM code, you have to assume write order always matters because you can’t tell the difference. This means inserting memory barriers after every write in the translated code. This absolutely kills performance.

Apple includes a special mode in their ARM chips, only used by Rosetta, that enables an x86-like strong memory model. This means Rosetta can translate x86 to ARM without inserting those performance-killing memory barriers. Unless Qualcomm added a similar mode (and AFAIK they did not) and Microsoft added support for it in their emulator, performance of translated x86 code is going to be nothing like that of Rosetta.

[–] olympicyes@lemmy.world 3 points 8 months ago

The biggest advantage Apple has is they’ve been breaking legacy compatibility every couple years, training devs to write more portable code and setting a consumer expectation of change. I can’t imagine how the emulator will cope with 32bit software written for the Pentium II.

[–] bitwolf@lemmy.one 3 points 8 months ago* (last edited 8 months ago) (2 children)

Qualcomm has a pretty fast emulator for the growing pains. Microscope offers arm versions for most of their software

But many open source projects could.be cross compiled it wouldn't be long if these things start selling.

[–] le_saucisson_masquay@sh.itjust.works 1 points 8 months ago (1 children)

Disagree, I run a MacBook m1 and enjoy it mostly because everything is compiled for arm. The very few software running through Rosetta are slow to launch, drain battery and less performant. If you were to run x64 on arm it just kill the interest of arm: battery becomes just as bad as on x64, performance is worst.

[–] modeler@lemmy.world 5 points 8 months ago (2 children)

Disagree with your disagreement. I also have an M1 and was a quite early adopter (within 3 months of launch). It was really snappy compared to my Intel Air it replaced. From the get-go. Even for apps that were still x86 code.

Things definitely improved over the next 9 months, but I was and am a really happy camper.

[–] jose1324@lemmy.world 1 points 8 months ago (1 children)

Intel Air doesn't count. Those were dogshit processors

[–] bitwolf@lemmy.one 2 points 8 months ago

Well decent processors, just laughably bad cooling design

I didnt use to run macOS before that but I’m surprised it could be worst, when using app through Rosetta it takes at least 2 or 3 seconds to launch and there is 20-30% more cpu usage. Although Its on my very limited pool of app (2) but even then you would be crazy to run macOS before, it would be more expensive than windows laptop for way less performance.

[–] MonkderZweite@feddit.ch 0 points 8 months ago* (last edited 8 months ago)

Qualcomm has a pretty fast emulator for the growing pains.

With how much, 10% or 20% performance loss? Better buy x86 then.

[–] abhibeckert@lemmy.world 2 points 8 months ago* (last edited 8 months ago) (1 children)

I don't know what these chips are like, but x86 software runs perfectly on my ARM Mac. And not just small apps either, I'm running full x86 Linux servers in virtual machines.

There is a measurable performance penalty but it's not a noticeable one with any of the software I use... ultimately it just means the CPU sits on 0.2 load instead of 0.1 load and if it spikes to 100% then it's only for a split second.

[–] olympicyes@lemmy.world 2 points 8 months ago

I recently bought an M1 Max and I definitely regret migrating data from my Intel MacBook. I’ve had to reinstall nearly all the apps anyway. Less compatible than I was expecting. Overall happy with it.

[–] BearOfaTime@lemm.ee 0 points 8 months ago (2 children)

MS has been working on ARM for years. To think otherwise is naive.

[–] dojan@lemmy.world 3 points 8 months ago (1 children)
[–] LordKitsuna@lemmy.world 0 points 8 months ago (1 children)

Linux has been a fully working on arm for much longer than Windows so there's that

[–] dojan@lemmy.world 1 points 8 months ago (1 children)

That’s not what I meant. Microsoft has been working on Windows ARM, sure, but has anyone else been working on Windows ARM? As far as I know you can’t even get Firefox on ARM.

I suppose that they have a compatibility layer, but it’s nowhere near the performance of Rosetta 2.

[–] LordKitsuna@lemmy.world 0 points 8 months ago (1 children)

Ah well, Firefox definitely has a Windows arm native build available on their website but yeah most applications certainly won't

[–] dojan@lemmy.world 1 points 8 months ago

Oh yeah, I stand corrected. I'm surprised I didn't see it before.

[–] abhibeckert@lemmy.world 1 points 8 months ago

Sure - but apple has been "working on" ARM since 1981. Microsoft is definitely on the back foot here.