[theaeolist]

Even if the Moore's law is not dead, single-thread performance and clock frequency have plateaued 10 years ago. This is the key factor. Because of heating even if you squeeze more transistors onto a chip you need to reduce the clock, so even if you may get higher computational throughput the latency will go down. And this is another argument for chiplets or any other alternative computational architectures.

[urthor]

> single-thread performance and clock frequency have plateaued 10 years ago

https://www.cpubenchmark.net/singleThread.html

It's amazing how often this is parroted. Anyone with a passing familiarity with the numbers knows this is actually not true at all.

Better caching, branch prediction, plus vast amounts of SRAM. There's been a slow & steady increase in the vast variety of single threaded workloads grouped together by "instructions per clock."

Both at the peak of the voltage frequency curve for workstations & overclocking, the apex of the optimization curve for data centre, and especially at the bare minimum for mobile devices with idle workloads.

Yes, it's a small fraction of the old days. It's still double in 10 years.

And as anyone who's migrated from an Intel Mac to Apple Silicon knows, "merely doubling" is a LOT.

[gilbetron]

Sorry, doubling in 10 years vs doubling in 18 months effectively is plateauing! Especially since it isn't really a consistent 10% growth per year, but a decelerating growth over that decade. Furthermore, much of the purported single thread performance is taken from a small set of benchmark tests, and so chip makers just optimize them for those tests. Generic single thread performance has undoubtedly not doubled in that 10 years.

[Uehreka]

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 this a plateau compared to the good old days of the 80s and 90s, but it’s definitely still progress.

[creshal]

> Have clock speeds really plateaued?

In late 2000, Intel promised that Pentium 4s will hit 10GHz by 2005 – on a presumed 130W power budget –, after the last 5 years saw clock speeds increase from 150MHz to 1.4GHz for the P6 architecture (at a stable 30-40W power budget), and other vendors saw similar increases.

Over 20 years later, we're barely scratching the 6GHz barrier with an opportunistic turbo mode that isn't guaranteed to kick in, if your cooling isn't up to the task of dissipating a record-breaking 250W of peak power consumption.

[dontlaugh]

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.

[michaelt]

> 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, where power efficiency is king.

[replygirl]

the frequency plateau always been a power consumption/leakage thing, and power draw for recent intel cpus only reinforces that. it's probably too early to tell if 6ghz is a new normal

and fwiw ive had a 5ghz+ overclock on every cpu ive bought in the last ten years with a corsair 240mm aio, going back to the 3570k

[loufe]

I really hope there are breakthroughs that allow us to use other, trickier, semiconductors like GaN for chips, IIUC their efficiency could allow us to hit much higher frequencies for the same heat output. That said, I doubt we'd see 3nm processes for something like that.

[actionfromafar]

latency up, but, yes.

[andreer]

IPC is still improving, so single thread performance is still increasing, even if clock speeds are not (at least not at the same as before). And new instructions (AVX ect) also help, especially if you can optimize and recompile your code.

It's at least enough that we have to take it into account:

We run our workloads across multiple Intel cpu generations and to be able to optimize utilization we have a "speedup factor" which is currently up to 1.7 for the latest generation we've tuned it for. And the base 1.0 performance is from Ivy Bridge, launched 2013.