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The Great CPU Stagnation

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Re: The Great CPU Stagnation

#101

Post by timerol »

moffkalast wrote: post #41
timerol wrote: post #28

Earlier quoted context omitted.

tl;dr New materials can help, but "resistive losses" aren't really the driving factor. The energy is a mix of leakage current and active current. Leakage current can be thought of as resistance - it's how much current flows through a transistor that's off. This can be better based on the material, but gets harder with smaller transistors. (Thinking about quantum tunneling as a resistance is good to get intuition, but…

From what I understand while these two do contribute a lot to power usage, they don't really contribute that much to heating by themselves? Leakage should happen all the same in a processor that's completely idle and those typically don't heat up much. For higher clock speeds specifically I still don't see how lower resistance isn't key.

> Leakage should happen all the same

Modern processors are very careful about this, and actively turn off the supply voltage to large parts of the die to prevent extra leakage current. The funny-but-appropriate name for this is "dark silicon" https://en.wikipedia.org/wiki/Dark_silicon

Re: The Great CPU Stagnation

#102

Post by neogodless »

EscapeFromNY wrote: post #30
mhh__ wrote: post #17

Earlier quoted context omitted.

The leading Arm chip (by apple) is arguably the best in class.

Apple's chips are very power efficent, yes, but the article and parent are talking/asking about raw power. Despite all the Intel hate the past 5 years, I don't think there's been even a moment where another company's leading chip has outperformed Intel's in benchmarks. See for example https://www.cpubenchmark.net/compare/4922vs5022vs5008vs5189/...

Umm, I added a readily available consumer CPU from a different company to your comparison chart.

https://www.cpubenchmark.net/compare/5022vs5008vs5189vs5031/...

Re: The Great CPU Stagnation

#103

Post by neogodless »

Reason077 wrote: post #4

The Great x86 CPU Stagnation? ARM seems to have made some great leaps forward in recent years.

Top AMD consumer x86 CPU over 4.5 generations:

https://www.cpubenchmark.net/compare/2966vs3238vs3598vs3862v...

I think the article is just about server CPUs getting better but the price is keeping them from being significantly better for the price. Of course, in these markets, any increase in power is justified such that the buyers are not price sensitive.

Re: The Great CPU Stagnation

#104

Post by sspiff »

This analysis is wrong because it is focusing on a limited number of high end chips.

You can buy CPUs that cost a fraction of any of those listed that will absolutely demolish even the best chips from 6 years ago today. All while consuming drastically less power for that performance as well.

Even mobile chips over 2 years old are within margin of error performance distance to those entry level Naples chips listed, at a fraction of the cost and power consumption.

I would not call that stagnation.

Re: The Great CPU Stagnation

#105

Post by jeron »

bhouston wrote: post #83

This "stagnation" is nothing like the stagnation during AMD's poorly performing Bulldozer era (the post Athlon era) where they were consistently beat by Intel's offerings and there was a general lack of innovation in the prosumer space. During that era for the most part Intel's i7 prosumer CPUs started with 4 cores with the Bloomfield Nehalem chips in 2008 (which at the time were awesome and a game changer) and ended…

the one good thing to come out of that era was the "moar cores" meme

Re: The Great CPU Stagnation

#106

Post by saltcured »

timerol wrote: post #100
saltcured wrote: post #42

Earlier quoted context omitted.

I thought leakage current would be the "DC" loss that is independent of frequency, like we had in old bipolar logic. Isn't it fair to characterize the cmos/fet switching losses as resistance to moving the charges around? I understand leakage will go up if we increase voltages to support higher switching speeds, but aren't there still a lot of losses that happen with logic transitions and reduce when the states are st…

> Isn't it fair to characterize the cmos/fet switching losses as resistance to moving the charges around? Not really. It makes more sense to think about it as filling and emptying capacitors. You are charging the gate capacitance up to the supply voltage, then dumping that charge to discharge the gate to 0 again. The energy of each capacitance that gets charged and dumped is CV^2/2, which happens for each logic trans…

So the charge is work and the discharge is waste?

I guess I am entertaining the idea of an idealized Maxwell-demon CMOS circuit, if we could bounce the charge between gates with very little work to just pump the charge back and forth.

Re: The Great CPU Stagnation

#107

Post by bhouston »

jeron wrote: post #105
bhouston wrote: post #83

This "stagnation" is nothing like the stagnation during AMD's poorly performing Bulldozer era (the post Athlon era) where they were consistently beat by Intel's offerings and there was a general lack of innovation in the prosumer space. During that era for the most part Intel's i7 prosumer CPUs started with 4 cores with the Bloomfield Nehalem chips in 2008 (which at the time were awesome and a game changer) and ended…

the one good thing to come out of that era was the "moar cores" meme

heh... https://9gag.com/gag/aRPw3xM

Re: The Great CPU Stagnation

#108

Post by sangnoir »

nologic01 wrote: post #47

In fact the CPU stagnation is worse. In contrast to the shrinking chip size and higher frequencies of past scaling laws, CPU core count does not easily translate to performance gains. It needs specialized and careful designed software to tap the capability. In fact if CPU core count did translate more easily to performance gains I think already with the existing CPU's we'd have a fairly signficant one-time boost. May…

> It needs specialized and careful designed software to tap the capability.

I wouldn't exactly call Golang[1] "specialized", but it does make multiprocessing easier than most languages.

1.Or Erlang or Elixir

Re: The Great CPU Stagnation

#109

Post by ianlevesque »

dietrichepp wrote: post #92
lynx23 wrote: post #44

The perfect time to shed ourselves of the idea that "optimisation is a waste of dev-time". Mobile computing was the last godsent t actually rethink performance a little bit, but we still have a lot of relatively low-hanging fruit. I sometimes dream about a month-of-no-new-features, where everyone would just have a bit of time to clean up and improve on existing stuff.

A more extreme version of that is “permacomputing”— https://permacomputing.net/projects/ I still regularly use old systems for fun. I grew up with Macs, so that’s the point of reference. When I use these old systems, I pine for a few specific things I’m used to on newer systems—but it almost feels like nitpicking. The things that I really want from a computer are pretty basic. Like good, consistent copy/paste and dra…

It's been a little frustrating watching iOS rip out literally all file management at launch and then slowly reintroduce it all feature by feature one at a time on iPad. Recently you can even mount network shares and use USB drives again.

Re: The Great CPU Stagnation

#110

Post by anonymousDan »

sspiff wrote: post #104

This analysis is wrong because it is focusing on a limited number of high end chips. You can buy CPUs that cost a fraction of any of those listed that will absolutely demolish even the best chips from 6 years ago today. All while consuming drastically less power for that performance as well. Even mobile chips over 2 years old are within margin of error performance distance to those entry level Naples chips listed, at…

Thanks, I was hoping someone would comment as to why the article might be wrong. I also wonder what the trends look like in terms of performance per watt?
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