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The Great CPU Stagnation

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Re: The Great CPU Stagnation

#23

The answer to this might be more application specific accelerators and 3D stacking. You can't afford to have all of a chip switched on at once because of the power consumption and dissipation, so you build more optimised accelerators and keep flipping between them as you encounter different pieces of code that may benefit from each accelerator. Only a fraction of the device is ever in use at once. You 3D stack the ch…

The industry term for the idea that most of your chip is switched off at any given time is “dark silicon”.

Re: The Great CPU Stagnation

#25
post #17
post #14

Earlier quoted context omitted.

I’m ignorant about this. Can a Qualcomm or Samsung chip match Intel’s raw power?

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

I'm well aware of Apple’s success since I’m surrounded by their devices at home. It seems to me it can’t be attributed only to ARM. What I wonder is where’re someone can match Intel on Intel’s playing field, like supplying ARM chips to laptop manufacturers that are better than Intel.

Re: The Great CPU Stagnation

#27

At least now people will start to focus on how bloated and slow software has become in the meantime. And stop referring to it as “tech”.

Containers killed the performance star.

I don't see how this could be true. Containers are just processes with some extra permissions applied.

Re: The Great CPU Stagnation

#28
post #2

We've known about this for a long time. Everyone expected it to happen. There are some key upcoming technologies that have the potential to cause a step in scaling (CFETs, backside power delivery) but it's still not going to be anywhere near Moore's law levels. I think this is part of why GPU power is skyrocketing and why Apple, Qualcomm, and the like are trying to shift towards services.

Well the main problem is resistance isn't it? Most of the power "used" is to get electrons to flow fast enough for the logic gates to settle for a specific clock frequency and the resistive losses to heat. The only real way forward that isn't a temporary workaround seems finding a new type of semiconductor that has lower overall resistance than silicon. Whoever figures out how to dope graphene and produce wafers with…

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 not good enough to help solve the problem. A material with a lower bulk resistivity will not help here.)

Active current is based on capacitance. Each FET has a little capacitor that needs to be charged and discharged every time the logic is switched - that adds up. Lowering the capacitance of each FET would reduce the energy required to switch it, but generally comes with bad tradeoffs. High-k dielectrics increase the capacitance, all other things being equal. But all other things are not equal, and they are used to create better performing FETs with lower power leakage.

Re: The Great CPU Stagnation

#30
post #17
post #14

Earlier quoted context omitted.

I’m ignorant about this. Can a Qualcomm or Samsung chip match Intel’s raw power?

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/...

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