CPU At Absolute Zero?

Discussion in 'Overclocking & Hardware' started by Benny11, Nov 3, 2009.

  1. Benny11

    Benny11 Member

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    Sorry if this post is in the wrong section but I didn't know where else to post it.

    I've always wondered what would happen if someone were to be able to cool a CPU to Absolute zero. I know (or have been taught) that semiconductors such as diodes and transistors become insulators at absolute zero and therefore would seize to work in a circuit. So if CPU's are made from millions of transistors... (They use silicone right?) then would a CPU seize to work at Absolute Zero as the cpu would now just be an insulator?

    I also apologize if this is the stupidest question you have ever heard, it's just one of those things I have always wondered.. ;)

    Thanks
     
    Last edited: Nov 3, 2009
  2. lawrencep93

    lawrencep93 Member

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    I don't think it would work, but it would be very hard to get it at absolute 0 and keep it there. Quite unpractical I'd say.
     
  3. 3stars

    3stars Member

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    considering that nobody can get to absolute zero doubt it
     
  4. salochin

    salochin Member

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    I assume you'd get some sort of super-conduction happening, probably wouldn't be good :Paranoid:

    There's not really any point going that cold though - light can only travel so far in one clock cycle, and at 6 or 7 Ghz the distance it can travel is starting to approach the width of the processor. If you went much faster signals wouldn't make it from one side of the die to the other in one clock cycle.
     
  5. Concept CBF

    Concept CBF Member

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    Yep you'd definatly have super-conductivity, bascially making the processor the equivilant to a square of metal :p.
     
  6. fnp

    fnp Member

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    It's impossible to attain absolute zero.
     
  7. Little Man

    Little Man Member

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    Not possible, but would be pretty cool though.:thumbup:
    Thanks for derailing me off my homework :tongue:
     
  8. karlcloudy

    karlcloudy Member

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    Has anyone ever used Liquid Helium (I think thats what it is) as a cooling method? It's supposed to be colder than LN2 I think, although I don't know a whole lot about science
     
  9. SLATYE

    SLATYE SLATYE, not SLAYTE

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    Superconductivity only occurs in certain elements. I don't think that silicon is one of them (regardless of how cold it gets). Copper, on the other hand, will superconduct at sufficiently low temperatures.

    As others have said, semiconductors become insulators.

    Rather more importantly, absolute zero implies that the system is completely disconnected from any other system (and the rest of the universe). The CPU has to be outside the universe if you want to achieve this, which will make using the computer an interesting challenge.

    As Salochin said, even if the CPU did become 'perfect' (ie everything that was meant to conduct became a superconductor and everything else became a perfect insulator) you'd still hit speed-of-light limitations.

    At 10GHz, light travels only 3cm per clock cycle. At this point the CPU may well be unable to actually remain synchronised (since many paths won't cross the chip by the shortest path).


    karlcloudy: yes, liquid helium has been used. It's very expensive and difficult to use (because it's a superfluid and it tends to climb the walls of whatever container it's in) but it can be done.
     
  10. yanman

    yanman Member

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    There was a new milestone for "hot" superconductivity recently, I think it was something like 19 Kelvin?
     
  11. lawrencep93

    lawrencep93 Member

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    I have seen a Pentium 4 overclocked to 8GHz and it still worked.
     
  12. Psychotik

    Psychotik Member

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    You cannot physically acheive absolute zero as there as is no way to remove every single piece of heat from an environment. I suspect that such extreme temperatures would render your CPU useless way before it ever gets to absolute zero (-273.15)
     
  13. SLATYE

    SLATYE SLATYE, not SLAYTE

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    For certain values of "work", anyway. It was running well enough that they could take a screenshot of CPU-Z. I suspect that if they used any reasonably complex instructions (that may actually require other parts of the CPU to be used) it would have failed.

    Much higher. They're past 100K. This means that liquid nitrogen (77K) can be used for cooling, rather than liquid helium.

    EDIT: One team appears to have managed 260K, although that's still very experimental.
     
    Last edited: Nov 3, 2009
  14. Autti

    Autti Member

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    Most processor bug out well before absolute zero anyway, the AMD Tweaker is an except and that was successfully clocked to 6.4Ghz iirc with Liquid Helium.
     
  15. EvilGenius

    EvilGenius Member

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    It's not about removing the heat so much as it is slowing the molecular motion to a point where it can't impart any energy to anything else. That part alone would make running a cpu at absolute zero impossible.

    ( yes I know that removing the heat and slowing molecular motion are pretty much the same thing, so perhaps it would be better to say instead that the above is a better way to phrase it...)

    If you somehow managed to achieve that state of molecular 'stillness', introducing an electrical current, basically turning the cpu on, would instantly disrupt that, unless of course as per slatye's post, someone dreams up a perfect insulator. Of course we're well into dream land by now :p
     
  16. karlcloudy

    karlcloudy Member

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    Yeah, well these extreme methods of cooling are really only good to demonstrate the best that the silicon can do and for a short period of time. Obviously the stress from going from such a cold temperature back to normal operating temperature wouldn't be great for the processor (and I assume the high voltage sustained would also destroy the processor in a short amount of time). It's nice to see whats possible though
     
  17. yanman

    yanman Member

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    Maybe I was thinking of -19C.. that's close to 260 Kelvin isn't it?
     
  18. EvilGenius

    EvilGenius Member

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    -19C is 254K (ignoring decimals). So close enough I guess.
     
  19. polyseal

    polyseal Member

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    was about to say something about absolute zero being no energy (apart from the zero point energy.. but anyways).

    if it was able to stay at absolute zero, with no atomic movement, would any charge flow? would the CPU even turn on? wouldnt you have a 0mhz cpu, or, the coldest paperweight?

    poly
     
  20. Potatos_69

    Potatos_69 Member

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    come now, lets be honest the coldest paperweight would still give u good e-peeeeeeeeeeeeeeen....
     

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