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On-CPU Peltiers From AMD?

Posted by timothy on from the speculatoryism dept.

Hack Jandy writes "Remember those people who lived on the edge and put peltiers between their CPU and heatsink (or your favorite beverage)? A peltier is a devices that gets cold on one side and warm on the other when an electrical current passes through it. It looks like there is talk that AMD will actually incorporate some of these devices on the CPU according to Xbitlabs. AMD already incorporates some degree of the peltier effect with it's Silicon on Insulator."

8 of 226 comments (clear)

  1. What about reliability? by Qzukk · · Score: 5, Insightful

    The problem with peltier coolers is that if it breaks down, the once cooling surface becomes an insulator. Plus, if the hot side gets too hot, the cooling process breaks down, so anyone using this would have to use a cooler that can draw the heat away as fast as the CPU-side peltier can kick it out, which would probably be another, larger peltier.

    I'd rather stick to external cooling systems that I can monitor and replace if necessary.

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    1. Re:What about reliability? by gl4ss · · Score: 5, Informative

      i don't think the realiability is the real issue.

      it seems xbitlabs is just.. well.. doing what journalist wannabees like - take some facts and twist them.

      for one: YOU DON'T GET MORE -EFFECTIVE- cooling with peltiers. you end up using more power than you would with normal cooling. the total heat output gets _increased_.

      unless they(chips) can't work in normal room temps there's not really much point in using peltier cooling in cooling them, except if you somehow manage to get the effect 'for free' or something.

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  2. Re:Heat by Rosonowski · · Score: 5, Informative

    Actually, the funny thing is, this hasn't been true for years. Intel CPUS put out quite a lot more wattage (~90w) compared to AMD's top end silicon, around 70 watts. But it made for a mildly funny joke back when the t-bird was spanking the socket 423 chips.

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  3. Peltiers? by polecat_redux · · Score: 5, Interesting

    I have had limited experience with Peltiers in the context of CPU overclocking, and I must say, my impression was that they're not all they're cracked up to be. Yeah, with a large enough cooler, you can drop the temp of the CPU significantly, but the effect is dependent on your ability to remove the heat from the other side (which is in excess of that given off by the CPU to begin with). A good water-cooling solution works well enough without the need for the extra drop in temp.

  4. Power... by PaintyThePirate · · Score: 5, Informative

    Just imagine the amount of power required for something like that. Each core of a dual core 65nm CPU will need at least 70 watts of power, giving 140 watts total. In order for a peltier to be useful, the wattage has to be greater than that of the CPUs. So with only the CPU and Pelt, that is a minimum of 300 watts, with something between 400 and 500 being more likely. That is an absurd amount of power and heat.

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  5. that's funny by Anonymous Coward · · Score: 5, Funny

    hot on one side, cold on the other. sounds like my bed.

  6. The problem with todays chips by doormat · · Score: 5, Insightful

    is not just the total amount of heat they put out, but the fact that they put out that much heat over an area of about one square centimeter (on the 90nm process at least). As the physical piece of silicon shrinks, the thermal density increases. More transistors switching on and off in a smaller area, and the drop in Vcc isnt enough to counteract the increase in density (we were at 1.8v or so with the 180nm process, and now at 90nm, we're at 1.4v or so - some chips dynamically change voltage and multiplier based on demand). I'm not sure this will do a whole lot of good if you just try to disapate the heat from the processor and the heat introducted by the peltier effect over the same square centimeter. You'd need to disapate the heat over a much larger area, say 10 sq cm. They you can stay in the realm of air-cooling instead of watercooling.

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    The Doormat

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  7. It seems they got it wrong... by Brane2 · · Score: 5, Informative

    AMD is patenting this as a way of *getting around* of SOI disadvantages. SOI means silicon on insulator , which is in this case SiO2, which is also excellent thermal (not only electrical) insulator. AMD says that SiO2 conducts heat at least hundred times less than silicon.

    What they are saying is that transistors on SOI might behave better, but they are certainly running hotter than their classic countepairs, since layer of SiO2 stands between them and the cooling system.

    So AMD is proposing several schemes of embedding TEC device into the insulating layer in the silicon. This layer would:

    1. Decrease overall thermal resisstance of the cooling path

    2. When powered on, offer bigger thermal diferential, since it could cool embedded side of the TEC significantly below the cooler temperature.

    It is unclear if they intend to use this on the whole chip, or just the especially hot areas...