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What holds back clockspeeds?

RainOfPain125

19 months ago

I know the faster the clockspeed, the more heat is produced. But lets just ignore that for now

What is stopping a CPU from overclocking faster and faster? Voltage? The architecture?

If neither of those were in play (temps, voltage, and architecture ignored) what would physically be stopping such an imaginary CPU from being clocked higher than what average CPU's can get to? I'm just plain curious on what "bottlenecks" stop a CPU from being clocked higher and higher (and, in what order those bottlenecks are in)

Comments

  • 19 months ago
  • 4 points

Usually it’s the design of the architecture, to put it in simple terms.

Smaller architectures like 22nm and 14nm chips have a hard time hitting higher clockspeeds due to their size and the amount of heat that’s produced. Also depends on how refined the architecture is. Broadwell is 14nm just like Kabylake but Broadwell was Intels first 14nm version of the Core series and took many generations (Skylake, Kaby Lake, Coffee Lake) to optimize the architecture.

Similar with Ryzen, although AMD is taking a different approach to their architecture.

  • 19 months ago
  • 3 points

I know the faster the clockspeed, the more heat is produced. But lets just ignore that for now

What is stopping a CPU from overclocking faster and faster?

You can't ignore that. Why do you think overclocking records are set using LN2?

  • 19 months ago
  • 1 point

I understand that LN is liquid nitrogen... but what is 2?

  • 19 months ago
  • 1 point

It's because it is two Nitrogen atoms.

  • 19 months ago
  • 1 point

Thanks

  • 19 months ago
  • 1 point

And that those CPU's usually have a super short life too.

  • 19 months ago
  • 2 points

You can't just ignore heat if you're wondering what's holding clock speeds down... Heat is pretty much the main reason...

  • 19 months ago
  • 1 point

Heat... Some of that can be dissipated with coolers and some is just gonna happen due to design... Heat is the big one though for clock speeds...

  • 19 months ago
  • 1 point

Architectural differences in power delivery and heat dissipation, combined with shrinking size of transistors/greater density of them. But the result ultimately is heat. More transistors means more heat output (not accounting for other differences), smaller transistors means less surface area for conductivity and less thermal mass, higher voltages reduce efficiency, and changes like the thermal interface material used... it all boils down to heat right now. That's why using extremely cold systems, enthusiasts can overclock to crazy heights.

If we completely disregarded heat and those other limitations, then the flow rate of electricity becomes an issue. It isn't instantaneous; it takes time to flip states on transistors. That would be the second issue.

Solving those two issues would take a quantum computer, but also its own host of issues in supporting such a system, such as actually using the streams of data. In essence, the bottleneck would lie elsewhere, whether it be code, cache, etc.

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