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Moore’s Law is dead – Long live the chiplet

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Re: Moore’s Law is dead – Long live the chiplet

#41

Post by MrFoof »

dontlaugh wrote: post #24
Uehreka wrote: post #22

Earlier quoted context omitted.

Have clock speeds really plateaued? Sure it’s not “double every 18 months”, but in mid 2018 I bought an Intel 8700K that turbo’d to 4.7GHz and could (with liquid metal, dark magic and luck) overclock to exactly 5GHz. I remember people saying progress was slowing down, that we might not make it to 6GHz. 4.5 years later and Intel is bragging that their upcoming topline CPU will run 6GHz stock. I suppose one could call…

Part of why that happens is Intel selling chips closer to the red line. You need cooling similar to what used to be exclusive to overclocking just to keep the stock CPU cool.

Yep. We're apparently finding out that it's mostly a waste of electricity to get an extra 5% performance due to how far outside the efficiency sweet spot chips are being pushed.

Not just Intel either. AMD has joined the game as of Zen 4, and NVIDIA's been playing it with their GPUs forever as well.

Zen 4 desktop CPUs appear to have (as expected) virtually unchanged single core performance, and maybe 5% reduced multi-core performance, on CPU-bound workloads by reducing the power limit to cut total power consumption -- by over a 100W reduction in the case of the new 7950X! Granted, Intel's been doing that forever -- reign in Alder Lake and its power consumption also comes way down, again for barely a performance hit in CPU-bound multi-core tasks.

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Enthusiast grade CPUs and GPUs are basically sold in the equivalent of a TV's retail "demo mode" now -- where a TV has max brightness, contrast and saturation that you'd NEVER use, but is intended to just grab a customer's attention as they walk by. Being pushed so far outside of their efficiency sweet spot just to get that extra 5% to "win benchmarks", when outside of specific use cases (and even if you actually need that 5%!) you're just consuming 50-100% more electricity for utterly marginal gains.

What a waste of resources! All so children (or people who still act like them) can feel better about a purchase as they argue on the internet over nothing worth arguing about.

Re: Moore’s Law is dead – Long live the chiplet

#42

Post by iggldiggl »

dagw wrote: post #37
michaelt wrote: post #27

Earlier quoted context omitted.

> Have clock speeds really plateaued? Pentium 4 HT 3.8F, November 2004, 3.8GHz, 115W TDP Core i9-13900KF, October 2022, 3.0GHz, 125W TDP Of course, the latter does give you 8 performance cores and 16 efficiency cores so performance-per-watt has clearly improved; and it has 'turbo boost'. But in terms of sustained single-core performance? It's clear Intel's attention has been elsewhere. Such as on the laptop market, w…

CPUMark single threaded score for the P4: ~620 CPUMark single threaded score for the 13900K ~4800 So obviously a lot has changed and improved.

And even in the Pentium 4 days, AMD CPUs managed similar performance as a Pentium 4 while running at lower clock speeds (which was a problem with some games that tried to auto-tune their performance-settings purely based on Pentium 4 clock speeds, even if you had an AMD CPU – thankfully at least in the Maxis/EA case, those settings were easily hackable, though, and could be easily adjusted to better match non-Pentium 4 CPUs, too).

Re: Moore’s Law is dead – Long live the chiplet

#43

Post by zozbot234 »

MrFoof wrote: post #41
dontlaugh wrote: post #24

Earlier quoted context omitted.

Part of why that happens is Intel selling chips closer to the red line. You need cooling similar to what used to be exclusive to overclocking just to keep the stock CPU cool.

Yep. We're apparently finding out that it's mostly a waste of electricity to get an extra 5% performance due to how far outside the efficiency sweet spot chips are being pushed. Not just Intel either. AMD has joined the game as of Zen 4, and NVIDIA's been playing it with their GPUs forever as well. Zen 4 desktop CPUs appear to have (as expected) virtually unchanged single core performance, and maybe 5% reduced multi-…

If you truly wanted to maximize performance per watt, you'd pick a very different design more reminiscent of GPU's. But then single-thread and low-multi-thread performance would really suck. So it will always be a carefully tuned tradeoff.

Re: Moore’s Law is dead – Long live the chiplet

#44

Post by tapanjk »

> Obviously, given these data, volume is VERY important in business models that operate with high fixed and low variable costs.

Off-topic but I wonder how much cheaper mobile phones would be if the manufacturers did not have to come up with a hardware design update every year or so? What if mobile phones were built to last longer, which would reduce the cost per phone due to high volume? Of course, I am not suggesting this is good for business but as a mere thought experiment.

Re: Moore’s Law is dead – Long live the chiplet

#45

Post by xattt »

zimpenfish wrote: post #35
cm2187 wrote: post #9

Earlier quoted context omitted.

2xxx

/1999|2\d{3}/ - "Dirk Hohndel, who was then the chief Linux and open-source technologist at Intel, predicted that in 1999, Linux would penetrate the PC desktop market and displace Windows."[1] [1] https://www.howtogeek.com/676963/why-desktop-linux-still-mat...

People in 1999 could not imagine Android devices.

Re: Moore’s Law is dead – Long live the chiplet

#46

Post by MrFoof »

zozbot234 wrote: post #43
MrFoof wrote: post #41

Earlier quoted context omitted.

Yep. We're apparently finding out that it's mostly a waste of electricity to get an extra 5% performance due to how far outside the efficiency sweet spot chips are being pushed. Not just Intel either. AMD has joined the game as of Zen 4, and NVIDIA's been playing it with their GPUs forever as well. Zen 4 desktop CPUs appear to have (as expected) virtually unchanged single core performance, and maybe 5% reduced multi-…

If you truly wanted to maximize performance per watt , you'd pick a very different design more reminiscent of GPU's. But then single-thread and low-multi-thread performance would really suck. So it will always be a carefully tuned tradeoff.

Nope. Not even. Again, as the grandparent post stated, everything is being sold with the default configuration being redlined.

You absolutely can reign it back in to sanity, and get better performance per watt over the previous gen, and still be noticeably faster over the previous gen.

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With AMD, apparently we're going to see BIOS updates from board manufacturers to make doing that simple. Set it to a lower power limit in a few keystrokes, still have something blazing fast (faster than previous gen), but use 145W instead of 250W. Or go even lower, still be a bit faster than previous gen while using around 88W on a 7950X instead of the 118W a 5950X did.

Intel -- who has been redlining their CPUs for years now -- even noted Raptor Lake's efficiency at lower power levels. Again, cut power consumption by 40-50%, for only a tiny performance hit. They actually made entire slides for their recent presentation highlighting this!

NVIDIA no different, and has been for years. Ampere stock voltages were well outside their sweet spot. Undervolt, cut power consumption by 20-25% and have performance UNCHANGED.

-- -----

Sure, there's more efficient stuff. Take last generation's 8-core Ryzen 7 PRO 5750GE. About 80% of the performance of an Intel Core i5-12600K, but only uses 38W flat out instead of 145W.

Re: Moore’s Law is dead – Long live the chiplet

#47

Post by mildmotive »

Ma8ee wrote: post #36
mildmotive wrote: post #33

Earlier quoted context omitted.

It’s offloading the cost to the customer. It is way cheaper to develop in some famous interpreted language than creating a set of robust compiled binaries. As long as customers can pay up for newer hardware we will keep seeing clunky UIs that can barely handle 20 list items of variable size without noticeable lag on a modern computer. I don’t even blame the companies for doing this. The benefit to cost ratio of using…

But the inefficiencies you sometimes see today can’t even be explained with any bad choice of language. You can create more than fast enough programs with interpreted languages with garbage collection. But then of course you need to know at least a little bit about data structures and not doing dozens of REST calls anytime anyone taps the screen.

I only partially agree, an interpreted language can act as a hinderance when doing optimisations, for various reasons.

But how we write the code also matters of course.

Furthermore, competency also costs money. I’m not saying this to be mean to people abusing REST calls.

Re: Moore’s Law is dead – Long live the chiplet

#48

Post by tyingq »

aargh_aargh wrote: post #19

For dummies like me who didn't know what a chiplet is: https://en.wikipedia.org/wiki/Chiplet This seems to be about the third reason listed: > Known good die (KGD): chiplets can be tested before assembly, improving the yield of the final device Problem: > In general, a killer defect is defined as a defect that is 20% the size of the fabrication node. For > example, a defect that is less than 9nm may be acceptable for…

AMD's EPYC-Rome processor, helpful to look at after looking at your link, as the chiplets are nice and visible:

https://cdn.wccftech.com/wp-content/uploads/2018/11/AMD-EPYC...

Re: Moore’s Law is dead – Long live the chiplet

#49

Post by somat »

I am not convinced moore's law no longer holds true, consider that there is a third dimension that no one has yet figured out.

I am no silicon engineer but I suspect a chip that fully takes advantage of the third dimension would be something like a sponge full of built in channels for the working fluid to remove heat.

First however I suspect you will see chiplets arranged vertically like heatsink fins and the whole cpu would effectively be the water block, basically a vlsi version of the cray 3

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