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ARM processors are starting to move up into the higher end as well, like servers. On an energy/computation basis they make more sense than x86 processors right

by asdf333 14y ago

ARM processors are starting to move up into the higher end as well, like servers. On an energy/computation basis they make more sense than x86 processors right now. The only issue is that software needs to be optimized for ARM processors but if the savings are there, this will happen pretty quickly. So I'd actually be worried for Intel as well. Not just AMD.

ajross 14y ago
There are certainly no server platforms that "make more sense" on a power/performance metric "right now". There are a few startups hawking their upcoming wares out there, but nothing I can buy with a credit card. And in any case at the very high end power/performance is still owned by Intel boxes (check the current record holders on Joulesort, for example).
iyulaev 14y ago
>> On an energy/computation basis they make more sense than x86 processors right now. Does anyone have ANY numbers that back this up? I've heard this refrain many many times but I've never seen any hard numbers to prove this. On a processor-per-processor basis sure an ARM SoC beats a Intel Xeon. But flop or dhrystone, x86s destroy ARM processors. In a virtualized world, where the number of real systems doesn't have to match the number of servers, x86 still appears to hold the lead.
- cmccabe 14y ago
  ARM cores tend to be more power efficient for three main reasons: they operate at a lower clock frequency, they don't have the CISC legacy baggage, and the low-level software guys have spent a lot more time on power management than on x86. It has to do with the evolutionary heritage of both systems. Most x86 systems are still sold to individuals or small businesses that will plug them into the wall and forget about power dissipation. A typical x86 desktop machine will draw between 300-500 watts. ARM evolved more for the cell phone and tablet market, and typical power consumption for one of those systems would be under 5 watts.
  - jrabone 14y ago
    A typical x86 desktop machine will draw between 300-500 watts. With a beefy GPU, perhaps. The new i3 3220T CPU is only 30W MAX TDP, flat out - a typical (ie. non-gamer) rig is looking more like 150W max, and a lot less idle (20W should be possible). Not 5W, but nowhere near 500W.
    - zanny 14y ago
      Yea, that metric seems bizarre. It is worth mentioning though that the lowest TDP chips Intel is selling are 17w mobile ones, comparing a desktop to a mobile chip seems apples and oranges. You also need to consider that Intel is at least a fab tech ahead of ARM chips. I have a Tegra 3 Transformer tablet and that chip was yielded at 40nm, 2 generations behind Intels 22nm, and it has a TDP of 15 watts. Of course under load it would run higher than that, but so would an Intel chip.
    - cmccabe 14y ago
      20W, 200W, what's the difference? Either way, you can't get that out of the battery on a mobile device. And consumers don't generally buy PCs based on power dissipation. Sad, but true. And if you think your typical beige-box PC can handle a power supply that is specc'ed for 150W-- go ahead and put one of those in there. I DARE you.
      - jrabone 14y ago
        The lower figure of 20W is pretty standard: go take a look at the battery in your laptop. Most Dells are 65Whr batteries - ie. 20W for 3 hours of battery life (to a first approximation, LiIon is a bit more complicated than that). The ubiquitous small form factor PCs like the Optiplex 780 (http://www.dell.com/downloads/global/corporate/environ/comply/optix_780_dccy.pdf http://www.dell.com/downloads/global/corporate/environ/compl...) use a 235W (max) power supply, which will be overspecced to trade off failure rates for manufacturing cost. Those machines actually draw less than 150W flat out. And they're everywhere. A certain large e-tailer with an emphasis on frugality used to use them as developer desktops(!). Who knows what's in a typical consumer beige box, but it isn't pulling 500W continuously, unless they're playing, say, Skyrim 24/7 with a big graphics card - in which case of course one would specify the correct (safe) component for the design. I'd argue that they're not typical by that point; most people won't spend £300 on a graphics card (I do).

by asdf333 14y ago

ajross 14y ago

There are certainly no server platforms that "make more sense" on a power/performance metric "right now". There are a few startups hawking their upcoming wares out there, but nothing I can buy with a credit card. And in any case at the very high end power/performance is still owned by Intel boxes (check the current record holders on Joulesort, for example).

iyulaev 14y ago

>> On an energy/computation basis they make more sense than x86 processors right now. Does anyone have ANY numbers that back this up? I've heard this refrain many many times but I've never seen any hard numbers to prove this. On a processor-per-processor basis sure an ARM SoC beats a Intel Xeon. But flop or dhrystone, x86s destroy ARM processors. In a virtualized world, where the number of real systems doesn't have to match the number of servers, x86 still appears to hold the lead.

cmccabe 14y ago
ARM cores tend to be more power efficient for three main reasons: they operate at a lower clock frequency, they don't have the CISC legacy baggage, and the low-level software guys have spent a lot more time on power management than on x86. It has to do with the evolutionary heritage of both systems. Most x86 systems are still sold to individuals or small businesses that will plug them into the wall and forget about power dissipation. A typical x86 desktop machine will draw between 300-500 watts. ARM evolved more for the cell phone and tablet market, and typical power consumption for one of those systems would be under 5 watts.
- jrabone 14y ago
  A typical x86 desktop machine will draw between 300-500 watts. With a beefy GPU, perhaps. The new i3 3220T CPU is only 30W MAX TDP, flat out - a typical (ie. non-gamer) rig is looking more like 150W max, and a lot less idle (20W should be possible). Not 5W, but nowhere near 500W.
  - zanny 14y ago
    Yea, that metric seems bizarre. It is worth mentioning though that the lowest TDP chips Intel is selling are 17w mobile ones, comparing a desktop to a mobile chip seems apples and oranges. You also need to consider that Intel is at least a fab tech ahead of ARM chips. I have a Tegra 3 Transformer tablet and that chip was yielded at 40nm, 2 generations behind Intels 22nm, and it has a TDP of 15 watts. Of course under load it would run higher than that, but so would an Intel chip.
  - cmccabe 14y ago
    20W, 200W, what's the difference? Either way, you can't get that out of the battery on a mobile device. And consumers don't generally buy PCs based on power dissipation. Sad, but true. And if you think your typical beige-box PC can handle a power supply that is specc'ed for 150W-- go ahead and put one of those in there. I DARE you.
    - jrabone 14y ago
      The lower figure of 20W is pretty standard: go take a look at the battery in your laptop. Most Dells are 65Whr batteries - ie. 20W for 3 hours of battery life (to a first approximation, LiIon is a bit more complicated than that). The ubiquitous small form factor PCs like the Optiplex 780 (http://www.dell.com/downloads/global/corporate/environ/comply/optix_780_dccy.pdf http://www.dell.com/downloads/global/corporate/environ/compl...) use a 235W (max) power supply, which will be overspecced to trade off failure rates for manufacturing cost. Those machines actually draw less than 150W flat out. And they're everywhere. A certain large e-tailer with an emphasis on frugality used to use them as developer desktops(!). Who knows what's in a typical consumer beige box, but it isn't pulling 500W continuously, unless they're playing, say, Skyrim 24/7 with a big graphics card - in which case of course one would specify the correct (safe) component for the design. I'd argue that they're not typical by that point; most people won't spend £300 on a graphics card (I do).