3 ms·

Agreed. A lot of people seem to think x86 has some inherent bottleneck that switching to ARM will magically bypass. Single core performance is currently doubli

by pansa2 6y ago

Agreed. A lot of people seem to think x86 has some inherent bottleneck that switching to ARM will magically bypass. Single core performance is currently doubling every five years or so. We’re not about to see it double in the next 24 hours.

m463 6y ago
> double in the next 24 hours there is a time-honored way to do exactly that. Constrain the comparison. "Double the performance" (of $899 to $901 laptops with 2560x1440 resolution) "Twice as fast" (as all laptops with thunderbolt 3 and no sd card reader)
- jedieaston 6y ago
  That's a fair comparison though, if you're a Mac user and this machine is twice as fast and gets 5 more hours on a charge, you'll probably be persuaded to upgrade. If you aren't a Mac user I don't think they need to convince you now, they need to convince the developers and artists to stay on the platform.
imtringued 6y ago
I've never understood this argument. For some reason there is this RISC vs CISC war debate but it's not actually based on reality of modern day chip design. The idea is that the decoder is consuming too much power and this design flaw cannot be fixed. Simplifying the decoder reduces the power consumption and therefore allows higher clock frequencies. But when we look at the clock frequencies of ARM and x86 chips we consistently see that x86 chips run at higher frequencies (roughly 4 Ghz for x86 and 2.7 Ghz for ARM). If there is a difference between ARM and x86 chips then it's not in the decoder. The difference must lie in the micro architecture of the chips and therefore RISC vs CISC is no longer relevant because the ISA is by definition not part of the micro architecture. Apple's ARM chips probably perform much better than reference ARM chips because they are much closer to the micro architecture that Intel uses. But Apple's chips still consume less power than Intel chips used in laptops. The secret sauce is probably the fact that the SoC has cores with different performance and power profiles. Big cores are used for peak performance bursts and lots of small cores for energy efficiency while the device is waiting for user input. I think Geekbench is measuring peak performance and not sustained performance but the numbers are probably correct. Making a representative comparison between mobile devices and desktops isn't possible because their different thermal profiles but it's highly likely that Apple will go for a passively cooled design if they can.
- unpossible 6y ago
  x64 chips can run at 4-5 GHz because these are desktop parts that can drop 10+ W sustained on a single core if need be. Power-frequency scaling tells us that of course this is very inefficient (perf/W), but efficiency isn't all, sometimes you just gotta go fast.

by pansa2 6y ago

m463 6y ago

> double in the next 24 hours there is a time-honored way to do exactly that. Constrain the comparison. "Double the performance" (of $899 to $901 laptops with 2560x1440 resolution) "Twice as fast" (as all laptops with thunderbolt 3 and no sd card reader)

jedieaston 6y ago
That's a fair comparison though, if you're a Mac user and this machine is twice as fast and gets 5 more hours on a charge, you'll probably be persuaded to upgrade. If you aren't a Mac user I don't think they need to convince you now, they need to convince the developers and artists to stay on the platform.

imtringued 6y ago

I've never understood this argument. For some reason there is this RISC vs CISC war debate but it's not actually based on reality of modern day chip design. The idea is that the decoder is consuming too much power and this design flaw cannot be fixed. Simplifying the decoder reduces the power consumption and therefore allows higher clock frequencies. But when we look at the clock frequencies of ARM and x86 chips we consistently see that x86 chips run at higher frequencies (roughly 4 Ghz for x86 and 2.7 Ghz for ARM). If there is a difference between ARM and x86 chips then it's not in the decoder. The difference must lie in the micro architecture of the chips and therefore RISC vs CISC is no longer relevant because the ISA is by definition not part of the micro architecture. Apple's ARM chips probably perform much better than reference ARM chips because they are much closer to the micro architecture that Intel uses. But Apple's chips still consume less power than Intel chips used in laptops. The secret sauce is probably the fact that the SoC has cores with different performance and power profiles. Big cores are used for peak performance bursts and lots of small cores for energy efficiency while the device is waiting for user input. I think Geekbench is measuring peak performance and not sustained performance but the numbers are probably correct. Making a representative comparison between mobile devices and desktops isn't possible because their different thermal profiles but it's highly likely that Apple will go for a passively cooled design if they can.

unpossible 6y ago
x64 chips can run at 4-5 GHz because these are desktop parts that can drop 10+ W sustained on a single core if need be. Power-frequency scaling tells us that of course this is very inefficient (perf/W), but efficiency isn't all, sometimes you just gotta go fast.