5 ms·

Interesting that you mention Apple/ARM -- don't forget that, eventually, Apple had no choice but to shift from PowerPC chips in its laptops and desktops to Inte

Interesting that you mention Apple/ARM -- don't forget that, eventually, Apple had no choice but to shift from PowerPC chips in its laptops and desktops to Intel. The performance difference was just too vast. I am fairly sure that the same thing will now happen with x86 and ARM -- it just depends on the timeline.

rbanffy 15y ago
Apple had to move to x86 because IBM wouldn't invest in development of a fast and low power processor for just one client (Apple) and Intel had a product (Core Duo) ready for them. One client, even Apple, is a very small market. Unit sales of ARM processors combined dwarf x86 sales and there is a huge market for higher performance ARM devices, something that didn't exist for PPC.
- fieldforceapp 15y ago
  That's correct. If you remember, Tim Cook described this limits on PPC based products as a "thermal problem" which is what drove them towards Intel. Presumably, ARM's licenses don't have this problem, in part, as @rbanffy implies, because the ARM architecture doesn't rely on a single source as the PPC did.
rsynnott 15y ago
That was rather different, as Apple was entirely dependent on IBM and Motorola to produce new chip designs (and Motorola had effectively quit the desktop market). The G5 was actually reasonably competitive with the P4 at the time the move was made, and beat it on some SIMD work. The real trouble was that IBM had repeatedly slipped on its deadlines to produce a low-power laptop-appropriate G5, and the aging G4 architecture just wasn't good enough. Today, the story is very different. Apple can produce its own SoC designs, as with the A5, or even produce its own ARM _core_ designs, like Qualcomm does, or it can buy from one of a number of healthy vendors who show no signs of quitting ARM anytime soon. If this Intel core had a genuine dramatic performance advantage over the A15 (which it will be competing with, given the timescales), at the same power usage, that would be one thing, but that's far from clear right now.
mikeash 15y ago
It wasn't just that Intel chips were faster. They also consumed less power. Just before the switch, Apple shipped a G5 desktop Mac with liquid cooling built in, which shows just how desperate the situation was for them. Things are much different now. Intel chips are faster than ARM, of course, but they are also vastly more power hungry. Power consumption matters more than speed in most devices these days (otherwise Intel would already be in everybody's phone) and will likely continue to do so for a long time. Intel shows no sign of being able to reduce their power consumption to the level needed while still retaining decent speed, whereas ARM shows every sign of being able to keep increasing their speeds while keeping power consumption where it needs to be.
- tedunangst 15y ago
  Granted that the graphs are coming from Intel, but assuming they're accurate I'd say it's a sign Intel can reduce power consumption and retain decent speed. http://www.anandtech.com/show/5365/intels-medfield-atom-z2460-arrive-for-smartphones http://www.anandtech.com/show/5365/intels-medfield-atom-z246...
  - mikeash 15y ago
    Maybe they can, but I'll believe it when they see it. Going by past accomplishments, ARM has done very well in making their chips faster, and Intel has not done so well in making their chips more economical. Certainly there could be a change in the game, but precedent heavily favors ARM in this one.
- Someone 15y ago
  Is that 'They also consumed less power' correct? http://datasheet.digchip.com/205/205-00367-0-970.pdf http://datasheet.digchip.com/205/205-00367-0-970.pdf gives typical power dissipation as 42W @1.8 GHz, 1.3v For a later design, http://datasheets.chipdb.org/IBM/PowerPC/970/PowerPC-970FX.pdf http://datasheets.chipdb.org/IBM/PowerPC/970/PowerPC-970FX.p..., section 3.1.5 gives 60W for the 2.2 GHz version at 105 degrees Celsius. http://en.wikipedia.org/wiki/List_of_Intel_Pentium_4_microprocessors http://en.wikipedia.org/wiki/List_of_Intel_Pentium_4_micropr... gives comparable values for the TDP for 2002-era Pentiums. I get the impression that IBM's data is real max (but 'Maximum power at 85 C is the ONLY value that is guaranteed by Manufacturing Test.'), while TDP may be lower than max (Reading http://en.wikipedia.org/wiki/Thermal_Design_Power http://en.wikipedia.org/wiki/Thermal_Design_Power) Or am I overlooking a factor for #CPUs? I always thought the water cooling was either an effort to decrease noise or over engineering or preparation for more cores and/or more speed (either of which were a necessity to keep up with Intel chips).

rbanffy 15y ago

Apple had to move to x86 because IBM wouldn't invest in development of a fast and low power processor for just one client (Apple) and Intel had a product (Core Duo) ready for them. One client, even Apple, is a very small market. Unit sales of ARM processors combined dwarf x86 sales and there is a huge market for higher performance ARM devices, something that didn't exist for PPC.

fieldforceapp 15y ago
That's correct. If you remember, Tim Cook described this limits on PPC based products as a "thermal problem" which is what drove them towards Intel. Presumably, ARM's licenses don't have this problem, in part, as @rbanffy implies, because the ARM architecture doesn't rely on a single source as the PPC did.

rsynnott 15y ago

That was rather different, as Apple was entirely dependent on IBM and Motorola to produce new chip designs (and Motorola had effectively quit the desktop market). The G5 was actually reasonably competitive with the P4 at the time the move was made, and beat it on some SIMD work. The real trouble was that IBM had repeatedly slipped on its deadlines to produce a low-power laptop-appropriate G5, and the aging G4 architecture just wasn't good enough. Today, the story is very different. Apple can produce its own SoC designs, as with the A5, or even produce its own ARM _core_ designs, like Qualcomm does, or it can buy from one of a number of healthy vendors who show no signs of quitting ARM anytime soon. If this Intel core had a genuine dramatic performance advantage over the A15 (which it will be competing with, given the timescales), at the same power usage, that would be one thing, but that's far from clear right now.

mikeash 15y ago

It wasn't just that Intel chips were faster. They also consumed less power. Just before the switch, Apple shipped a G5 desktop Mac with liquid cooling built in, which shows just how desperate the situation was for them. Things are much different now. Intel chips are faster than ARM, of course, but they are also vastly more power hungry. Power consumption matters more than speed in most devices these days (otherwise Intel would already be in everybody's phone) and will likely continue to do so for a long time. Intel shows no sign of being able to reduce their power consumption to the level needed while still retaining decent speed, whereas ARM shows every sign of being able to keep increasing their speeds while keeping power consumption where it needs to be.

tedunangst 15y ago
Granted that the graphs are coming from Intel, but assuming they're accurate I'd say it's a sign Intel can reduce power consumption and retain decent speed. http://www.anandtech.com/show/5365/intels-medfield-atom-z2460-arrive-for-smartphones http://www.anandtech.com/show/5365/intels-medfield-atom-z246...
- mikeash 15y ago
  Maybe they can, but I'll believe it when they see it. Going by past accomplishments, ARM has done very well in making their chips faster, and Intel has not done so well in making their chips more economical. Certainly there could be a change in the game, but precedent heavily favors ARM in this one.
Someone 15y ago
Is that 'They also consumed less power' correct? http://datasheet.digchip.com/205/205-00367-0-970.pdf http://datasheet.digchip.com/205/205-00367-0-970.pdf gives typical power dissipation as 42W @1.8 GHz, 1.3v For a later design, http://datasheets.chipdb.org/IBM/PowerPC/970/PowerPC-970FX.pdf http://datasheets.chipdb.org/IBM/PowerPC/970/PowerPC-970FX.p..., section 3.1.5 gives 60W for the 2.2 GHz version at 105 degrees Celsius. http://en.wikipedia.org/wiki/List_of_Intel_Pentium_4_microprocessors http://en.wikipedia.org/wiki/List_of_Intel_Pentium_4_micropr... gives comparable values for the TDP for 2002-era Pentiums. I get the impression that IBM's data is real max (but 'Maximum power at 85 C is the ONLY value that is guaranteed by Manufacturing Test.'), while TDP may be lower than max (Reading http://en.wikipedia.org/wiki/Thermal_Design_Power http://en.wikipedia.org/wiki/Thermal_Design_Power) Or am I overlooking a factor for #CPUs? I always thought the water cooling was either an effort to decrease noise or over engineering or preparation for more cores and/or more speed (either of which were a necessity to keep up with Intel chips).