Why has CPU frequency ceased to grow? (2014)

Post by brobinson » Thu, Feb 22, 2018, 1:16 AM UTC

quadcore wrote: post #10

mjfl wrote: post #8

I took a class that went over this in depth like 3-4 years ago. Basically the message was that serial performance is saturating, and the only way to get speed improvements in the future is going to be by exploiting parallelism. However, most programmers, and programming languages, remain stuck in a serial-by-default paradigm. I'm surprised that there hasn't emerged a "parallel-by-default C++" kind of language + hardw…

https://golang.org/ In case you dont know, Golang goroutines are a marvel of parallelism. They are coroutines which are dispatched on a few OS threads. So you can use 100% of a multi-cores CPU and yet, spawn, say, 10K of those light threads without worrying about context switches PLUS have them all run concurrently. I've found that golang is one of those rare language, like Lisp, that actually change the way you thin…

Post by deepnotderp » Thu, Feb 22, 2018, 1:34 AM UTC

ska wrote: post #239

z3t4 wrote: post #165

Earlier quoted context omitted.

I kinda regret adding the note about performance, because switching to a lower level language used to yield orders of magnitude more performance, but optimizers have evolved and today there's not much difference. Sometimes the higher level language will be even faster because of optimizations. And bad performance is often not to blame on the language, instead blame the programmer or more likely the business people as…

used to yield orders of magnitude more performance, but optimizers have evolved and today there's not much difference. If this were true, you'd expect see a lot more native python and the like.

Post by deepnotderp » Thu, Feb 22, 2018, 1:41 AM UTC

tagrun wrote: post #253

tarlinian wrote: post #210

Earlier quoted context omitted.

Transistor switching frequency has almost nothing to do with processor clock speeds which are almost entirely limited by wire RC delay. You will get increased drive currents by switching to higher mobility materials but the performance improvement over strained silicon isn't that large.

That's just a plumbing problem which can be solved by lowering temperature or using a different material with lower resistivity. Yes, it'll probably cost more, but it's a problem that can readily be solved. But if your switching frequency is slow, it doesn't matter if you use a superconductor for wires. It is the switching frequency that truly determines the limits for gate times, which in turn determines how fast yo…

Post by deepnotderp » Thu, Feb 22, 2018, 1:44 AM UTC

whoisthemachine wrote: post #71

My senior design course focused on asynchronous (clock-less) cryptography circuits; after learning of these, I looked into asynchronous general purpose processors, and learned that ARM actually designed an asynchronous processor back in the 2000's [0]. While they've never quite taken off (the extra gates decrease speed and our harder to manufacture), with the recent side-channel attacks on processor pipelines, I've b…

Post by Const-me » Thu, Feb 22, 2018, 2:30 AM UTC

quadcore wrote: post #10

mjfl wrote: post #8

I took a class that went over this in depth like 3-4 years ago. Basically the message was that serial performance is saturating, and the only way to get speed improvements in the future is going to be by exploiting parallelism. However, most programmers, and programming languages, remain stuck in a serial-by-default paradigm. I'm surprised that there hasn't emerged a "parallel-by-default C++" kind of language + hardw…

https://golang.org/ In case you dont know, Golang goroutines are a marvel of parallelism. They are coroutines which are dispatched on a few OS threads. So you can use 100% of a multi-cores CPU and yet, spawn, say, 10K of those light threads without worrying about context switches PLUS have them all run concurrently. I've found that golang is one of those rare language, like Lisp, that actually change the way you thin…

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