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> There’s really no way to understate what a colossal achievement Apple’s M1 processor is; compared with almost every modern x86-64 processor in its class On t

> There’s really no way to understate what a colossal achievement Apple’s M1 processor is; compared with almost every modern x86-64 processor in its class On the other hand I'm sure there's more than a few chipheads out there who are saying "it's about time", there was a longstanding prediction that the arm architecture would overtake x86.

AnthonyMouse 5y ago
> there was a longstanding prediction that the arm architecture would overtake x86. So now the wheel turns and someone will have to predict how long it takes before RISC-V overtakes ARM.
- rpmisms 5y ago
  I'd be willing to bet Apple will catalyze that change as well.
  - fartcannon 5y ago
    Only if they can lock it down.
    - GoOnThenDoTell 5y ago
      They can make their own extensions
- mhh__ 5y ago
  I'm not totally convinced that'll happen in the desktop space. Embedded, I completely buy it, but I have read fairly convincing arguments that ARM might be a better ISA for really high-performance architectures. RISC-V also seems to value compressed instructions far too much, so we could see a high-performance fork of RISC-V?
  - urthor 5y ago
    Given how much cruft x86 has, there's a comments about world class experts above saying the gap between ARM and x86 is maybe 5%, at best, and probably less. There's realistically probably no reason RISC-V cannot work, expect that the number of techniques needed to implement a leading edge high performance evaluator is enormous.
- zozbot234 5y ago
  RISC-V has a few ISA advantages over ARM64 (mainly the variable length instructions, which provide instruction density that's comparable with x86 while still being very easy to decode) but meaningful competition would have to come from something more like the upcoming Mill architecture - VLIW-like power efficiency with the same flexibility and IPC as current OOO designs.
  - floatboth 5y ago
    RISC-V has some bad ISA disadvantages like needing three (!) instructions for array indexing: https://gist.github.com/erincandescent/8a10eeeea1918ee4f9d9982f7618ef68 https://gist.github.com/erincandescent/8a10eeeea1918ee4f9d99... Isn't Mill eternal vaporware?
mhh__ 5y ago
It is about time, although it is worth saying that a bunch of the chips here are actually basically ancient due to being released years ago, or being fairly old microarchitectures. Hat's off to Apple, of course, but Intel were sort of a victim of their own success in that they nearly beat AMD to extinction over the last decade. I also note that there's no comparison with a properly modern X86 (i.e. an AMD 5000 series). The Apple will still come up on top, most likely, but that Xeon did literally come out in 2012!
- trissylegs 5y ago
  Almost might see intel actually come out with a new process node in the next year. Which is a long time coming.
throwawaylinux 5y ago
I thought the observation was always that instruction set was not such a big difference in high performance CPUs next to manufacturing technology which was by far the first order effect. It would be expected for a high performance ARM CPU to reach roughly the same performance in that case (AMD is 1 generation behind here, I think Intel is 2). Is there really "chipheads" who are predicting ARM ISA to buck this trend and start pulling ahead at equivalent technology nodes? By what mechanism do they believe this will happen, do you know?
- entee 5y ago
  Not a chiphead, but saw this in the article that might be a reason ARM is better for this kind of thing: "The theory goes that arm64’s fixed instruction length and relatively simple instructions make implementing extremely wide decoding and execution far more practical for Apple, compared with what Intel and AMD have to do in order to decode x86-64’s variable length, often complex compound instructions." Not sure it's true, not an expert. But it doesn't sound wrong!
  - throwawaylinux 5y ago
    The fixed width decoders have always been a commonly cited advantage of fixed width, and to some degree it must be true. But this is not a recent thing, the "common wisdom" about instruction format not mattering too much still very much applies here. Pre-decode lengths or stop-bits and more recently micro-op caches have been techniques that x86 has used to mitigate this and improve front end widths, for example. People like Jim Keller (who has actually worked and lead teams implementing these very processors at Apple, Intel, and AMD!) basically say as much (while acknowledging decode is a little harder, in the large scheme of things on modern large cores it's not such a big deal): https://chipsandcheese.com/2021/07/13/arm-or-x86-isa-doesnt-matter/ https://chipsandcheese.com/2021/07/13/arm-or-x86-isa-doesnt-... Andy Glew, one of the architects for Intel's first out of order x86 core (P6) among other things, is another who has said similar. https://groups.google.com/g/comp.arch/c/elke1FHfYr0/m/SwW9NT1x2gMJ https://groups.google.com/g/comp.arch/c/elke1FHfYr0/m/SwW9NT...
    - 5y ago
adfrhgeaq5hy 5y ago
I think that person meant "overstate". The ISA has relatively little to do with it. Sure, x86 requires power-hungry decoders, but most of the time you'll be running from the uop cache anyway. Plus you get denser code. Arm and x86 aren't all that different under the hood these days and generally RISC vs CISC is a wash. It took heroic engineering to get x86 that fast, but that work is already done.
acomjean 5y ago
x86 is quite a bit older instruction set. It has a lot of cruft and the all chips are really backward compatible with older software and many operating systems. Its extremely flexible at a cost to performance. The new Apple chips while impressive, only run new ARM64 instruction set programs compiled for apple machines. Depending on your use case that might not matter, but its still something. And competition is good for a cpu market that was lacking the massive year to year improvements of 20 years ago..
rob74 5y ago
Yeah, your quote is a bit unfair to x86 - after all the x86 architecture is hampered by having to maintain compatibility not only with the original 8086, but also with most other instruction set extensions that Intel and/or AMD came up with during the last 40 years. Compared to that, the M1 is almost a "clean sheet" design. So, while still a great achievement, its dramatically better efficiency is not that surprising. I wonder however if Apple leading the way will also enable the PC (Windows/Linux) platform to leave its x86 past behind. Microsoft has been trying to sell ARM-based tablets for years, but without a lot of success, because there's not enough native software available.
- josephg 5y ago
  > So, while still a great achievement, its dramatically better efficiency is not that surprising. Is it? I was under the impression modern CPUs translate x86 instructions do on the fly translation to something else anyway. I’d be very surprised if that hardware translation process was making their chips 4x less power efficient (or whatever the number is). Also as a consumer, the reasons why x86 stayed around as long as it did sound like a bunch of excuses. If x86 is really as inefficient as you say, then it’s about time the industry started sidelining Intel and moving to a better architecture with or without them. I’m hoping AMD follows suit before long and starts selling competitive arm or risc-v chips.
- zamadatix 5y ago
  Windows ARM failure to take of so far seems more likely to do with the relative underperformance of Qualcomm chips not the lack of software. Especially since in recent years you've been able to run x86 software anyways. Windows 10/11 on an M1 Mac via parallels however has been the best Windows ARM device I've ever used and I have no trouble using it daily as my main work laptop.

AnthonyMouse 5y ago

> there was a longstanding prediction that the arm architecture would overtake x86. So now the wheel turns and someone will have to predict how long it takes before RISC-V overtakes ARM.

rpmisms 5y ago
I'd be willing to bet Apple will catalyze that change as well.
- fartcannon 5y ago
  Only if they can lock it down.
  - GoOnThenDoTell 5y ago
    They can make their own extensions
mhh__ 5y ago
I'm not totally convinced that'll happen in the desktop space. Embedded, I completely buy it, but I have read fairly convincing arguments that ARM might be a better ISA for really high-performance architectures. RISC-V also seems to value compressed instructions far too much, so we could see a high-performance fork of RISC-V?
- urthor 5y ago
  Given how much cruft x86 has, there's a comments about world class experts above saying the gap between ARM and x86 is maybe 5%, at best, and probably less. There's realistically probably no reason RISC-V cannot work, expect that the number of techniques needed to implement a leading edge high performance evaluator is enormous.
zozbot234 5y ago
RISC-V has a few ISA advantages over ARM64 (mainly the variable length instructions, which provide instruction density that's comparable with x86 while still being very easy to decode) but meaningful competition would have to come from something more like the upcoming Mill architecture - VLIW-like power efficiency with the same flexibility and IPC as current OOO designs.
- floatboth 5y ago
  RISC-V has some bad ISA disadvantages like needing three (!) instructions for array indexing: https://gist.github.com/erincandescent/8a10eeeea1918ee4f9d9982f7618ef68 https://gist.github.com/erincandescent/8a10eeeea1918ee4f9d99... Isn't Mill eternal vaporware?

mhh__ 5y ago

It is about time, although it is worth saying that a bunch of the chips here are actually basically ancient due to being released years ago, or being fairly old microarchitectures. Hat's off to Apple, of course, but Intel were sort of a victim of their own success in that they nearly beat AMD to extinction over the last decade. I also note that there's no comparison with a properly modern X86 (i.e. an AMD 5000 series). The Apple will still come up on top, most likely, but that Xeon did literally come out in 2012!

trissylegs 5y ago
Almost might see intel actually come out with a new process node in the next year. Which is a long time coming.

throwawaylinux 5y ago

I thought the observation was always that instruction set was not such a big difference in high performance CPUs next to manufacturing technology which was by far the first order effect. It would be expected for a high performance ARM CPU to reach roughly the same performance in that case (AMD is 1 generation behind here, I think Intel is 2). Is there really "chipheads" who are predicting ARM ISA to buck this trend and start pulling ahead at equivalent technology nodes? By what mechanism do they believe this will happen, do you know?

entee 5y ago
Not a chiphead, but saw this in the article that might be a reason ARM is better for this kind of thing: "The theory goes that arm64’s fixed instruction length and relatively simple instructions make implementing extremely wide decoding and execution far more practical for Apple, compared with what Intel and AMD have to do in order to decode x86-64’s variable length, often complex compound instructions." Not sure it's true, not an expert. But it doesn't sound wrong!
- throwawaylinux 5y ago
  The fixed width decoders have always been a commonly cited advantage of fixed width, and to some degree it must be true. But this is not a recent thing, the "common wisdom" about instruction format not mattering too much still very much applies here. Pre-decode lengths or stop-bits and more recently micro-op caches have been techniques that x86 has used to mitigate this and improve front end widths, for example. People like Jim Keller (who has actually worked and lead teams implementing these very processors at Apple, Intel, and AMD!) basically say as much (while acknowledging decode is a little harder, in the large scheme of things on modern large cores it's not such a big deal): https://chipsandcheese.com/2021/07/13/arm-or-x86-isa-doesnt-matter/ https://chipsandcheese.com/2021/07/13/arm-or-x86-isa-doesnt-... Andy Glew, one of the architects for Intel's first out of order x86 core (P6) among other things, is another who has said similar. https://groups.google.com/g/comp.arch/c/elke1FHfYr0/m/SwW9NT1x2gMJ https://groups.google.com/g/comp.arch/c/elke1FHfYr0/m/SwW9NT...
  - 5y ago

adfrhgeaq5hy 5y ago

I think that person meant "overstate". The ISA has relatively little to do with it. Sure, x86 requires power-hungry decoders, but most of the time you'll be running from the uop cache anyway. Plus you get denser code. Arm and x86 aren't all that different under the hood these days and generally RISC vs CISC is a wash. It took heroic engineering to get x86 that fast, but that work is already done.

acomjean 5y ago

x86 is quite a bit older instruction set. It has a lot of cruft and the all chips are really backward compatible with older software and many operating systems. Its extremely flexible at a cost to performance. The new Apple chips while impressive, only run new ARM64 instruction set programs compiled for apple machines. Depending on your use case that might not matter, but its still something. And competition is good for a cpu market that was lacking the massive year to year improvements of 20 years ago..

rob74 5y ago

Yeah, your quote is a bit unfair to x86 - after all the x86 architecture is hampered by having to maintain compatibility not only with the original 8086, but also with most other instruction set extensions that Intel and/or AMD came up with during the last 40 years. Compared to that, the M1 is almost a "clean sheet" design. So, while still a great achievement, its dramatically better efficiency is not that surprising. I wonder however if Apple leading the way will also enable the PC (Windows/Linux) platform to leave its x86 past behind. Microsoft has been trying to sell ARM-based tablets for years, but without a lot of success, because there's not enough native software available.

josephg 5y ago
> So, while still a great achievement, its dramatically better efficiency is not that surprising. Is it? I was under the impression modern CPUs translate x86 instructions do on the fly translation to something else anyway. I’d be very surprised if that hardware translation process was making their chips 4x less power efficient (or whatever the number is). Also as a consumer, the reasons why x86 stayed around as long as it did sound like a bunch of excuses. If x86 is really as inefficient as you say, then it’s about time the industry started sidelining Intel and moving to a better architecture with or without them. I’m hoping AMD follows suit before long and starts selling competitive arm or risc-v chips.
zamadatix 5y ago
Windows ARM failure to take of so far seems more likely to do with the relative underperformance of Qualcomm chips not the lack of software. Especially since in recent years you've been able to run x86 software anyways. Windows 10/11 on an M1 Mac via parallels however has been the best Windows ARM device I've ever used and I have no trouble using it daily as my main work laptop.