Researchers Demonstrate In-Chip Watercooling (arstechnica.com) 42
FallOutBoyTonto shares a report from Ars Technica: Part of the problem with liquid cooling solutions is that they're limited by having to get the heat out of the chip and into the water in the first place. That's led some researchers to consider running the liquid through the chip itself. Now, some researchers from Switzerland have designed the chip and cooling system as a single unit, with on-chip liquid channels placed next to the hottest parts of the chip. The results are an impressive boost in heat-limited performance.
There have been a number of demonstrations of on-chip liquid cooling. These typically involve a system where a device with a set of liquid channels is fused onto a chip, and a system pumps fluid through it. This can get heat off the chip, and initial implementations have found that there's a bit of a trade-off: it takes more power to pump the water through these channels than you extract from the processor. That power isn't used at the site where heat is an issue, so it doesn't get in the way of the heat dissipation, but it does cut into the energy efficiency of the system. The new research builds upon these ideas to boost the efficiency of on-chip cooling systems. And the researchers involved demonstrate that it works using a power-converting chip that otherwise would see the performance reduced by the heat. The research has been published in the journal Nature.
There have been a number of demonstrations of on-chip liquid cooling. These typically involve a system where a device with a set of liquid channels is fused onto a chip, and a system pumps fluid through it. This can get heat off the chip, and initial implementations have found that there's a bit of a trade-off: it takes more power to pump the water through these channels than you extract from the processor. That power isn't used at the site where heat is an issue, so it doesn't get in the way of the heat dissipation, but it does cut into the energy efficiency of the system. The new research builds upon these ideas to boost the efficiency of on-chip cooling systems. And the researchers involved demonstrate that it works using a power-converting chip that otherwise would see the performance reduced by the heat. The research has been published in the journal Nature.
Cooling 1700 W / cm chips (Score:4, Interesting)
They manage to keep a 1700 W / cm chip at 60 C. That seems quite impressive.
Re: (Score:2)
One might even wonder how the water didn't change to steam at that power level.
The only explanation is that there's not much square cm, and that this probably can't scale to a Pentium.
Re: (Score:2)
Re: (Score:2)
Yeah, that doesn't add up.
1cc of water at 20C should hit boiling in around ~0.2 seconds with 1700w of heat input.
Re: (Score:2)
If the water is kept under pressure it can take more than 100C before turning into steam...
Re: (Score:2)
But how does that keep the chip at 60C???
Re: (Score:2)
Hello 6Ghz intel chip.
Re:Cooling 1700 W / cm chips (Score:4, Informative)
Re:Cooling 1700 W / cm chips (Score:4, Interesting)
I meant 1700 Watts per square centimeter at 60 degree Celsius.
That is about 100 times the power density of the burner on an electric stove.
Re: (Score:2)
Or about 2.5x AMD Athlon CPUs.
Re: Cooling 1700 W / cm chips (Score:1)
I think we can safely assime that the chip was *tiny*. And the pipes large.
Meaning that it won't scale with those numbers. As the inlets and outlets, where the tiny canals join, will be the bottleneck.
Re:Cooling 1700 W / cm chips (Score:4, Interesting)
For a cooling solution to be feasible you can't have limitless supply of cold water like when using tap water or options like dumping ice cubes into your water tank. If you use active chilling that is essentially a refrigerator, that should be noted as well.
I also wonder how longevity plays out for water cooling in these scenarios. So what kind of fluids are they're going to use for their primary loops at least, which won't lead to significant corrosion over time and or buildup of micro-organisms.
Classical water cooling can be replaced and maintained easily enough. Integrated water cooling however seems to make things a bit more complicated.
Re:Cooling 1700 W / cm chips (Score:5, Informative)
The challenge is to remove 1700W from a square centimeter of chip area. That's the difficult part. Getting that heat somewhere else is the easy part and a solved problem. The ICE in a car expels more heat than that (1700W is around 2 1/2HP of heat). Even a basic air conditioner can remote 1700W of heat - for a typical COP of 5 or 6, the AC only consumes around 300W of power to move that much.
Of course, the chips with this will likely have their own dedicated cooling systems - you aren't using this in a PC since a 1700W chip and cooling solution will require a 240V source. And you'd need a room cooling system since your room would get quite warm in short order
Re: (Score:2)
That doesn't solve the longevity problems though. AC uses gas, for example, not liquid. Cars have huge radiators and large tubing so a bit of build up isn't much of a problem.
Look at all-in-one water cooling solutions for current PCs. Basically a radiator, CPU block and a pump all in one. Factory sealed. Some come with a 5 year warranty but many people are finding they fail in less than 2 due to contamination in the water or mixed metals leading to clogging.
Re: (Score:2)
It would probably be a better idea to run refrigerant through the chip. The chip can be the evaporator in an A/C system. But you've got to start somewhere.
Re: (Score:2)
Your basic idea is probably right, the correct refrigerant might be better than water. However, you have a couple of things wrong.
Water used to transfer heat is a refrigerant, specifically R718.
Using a phase-change to help capture more heat is probably a bad idea in this system. Keep it simple. Avoid the bubbling that may cause erosion in these small parts. Avoid the gaseous phase that will require larger channels due to lower density.
Re: (Score:2)
Standard A/C uses a fluid vapor that is gas and liquid sequentially. A liquid that is evaporated when pressure is reduced to cool at low temperature, is compressed to raise its' temperature, then is cooled to ambient temperatures to condense it back to a liquid.
Re: (Score:2)
Re: (Score:2)
That doesn't solve the longevity problems though. AC uses gas
Stop right there. You don't need AC to provide 1700W of cooling. Hell most high end watercooled rigs have the capability (not the necessity) to do that just by circulating water through large enough radiators.
When sizing a system, it's important to remember it is in fact a system and there are many variables involved.
Re: (Score:2)
Look at all-in-one water cooling solutions for current PCs. Basically a radiator, CPU block and a pump all in one. Factory sealed. Some come with a 5 year warranty but many people are finding they fail in less than 2 due to contamination in the water or mixed metals leading to clogging.
I hate to double reply but no that could not be further from the truth. There are very few AIOs which actually fail within their warranty period. Guess what, shitty products exist. That doesn't make it the norm.
Re: Cooling 1700 W / cm chips (Score:1)
As somebody who had water cooling:
Do NOT replace the water! Each time you do that, you damage the thing a bit more. (And risk getting air bubbles, if done wrong.)
You make sure the water isn't harmful in the first place. In this case you could use highly purified water, and/or add glycol. At least we used to do that.
Transformer oil is great too. IF the cirquit is *closed* and unopenable. Because somebody tried it on a normal PC, and the stuff crept under the plastic of the mouse cable, up, and spread over th
Re: Very interesting (Score:1)
Countless people suggested that for decades.
I was one of them.
Or ... (Score:2)
Simply immerse the entire circuitry in Fluorinert [wikipedia.org] like with the Cray 2 [wikipedia.org]. I was an administrator for the one, named "voyager", at NASA LaRC back in the '80s and it was pretty cool. I wanted to put plastic fish inside the case, but they said no. :-(
They/we also had a Cray Y-MP ("sabre") and several Convex [wikipedia.org] minisupercomputers ("phantom", "mustang", "eagle") and several StorageTek Tape Silos.
Re: (Score:2)
That would not be as effective as running the liquid through the CPU core.
Re: (Score:2)
That would not be as effective as running the liquid through the CPU core.
True, but Fluorinert immersion could be done with any system, not just ones designed for it. On the other hand, Fluorinert is expensive -- like $400/kg and I read that FC liquids are 2x heavier than water -- so your wallet may not approve.
Re: (Score:2)
Re: (Score:2)
and the permits to use it would take another wallet bite...
Hey, anything worth doing is worth way over-doing. :-)
Re: (Score:2)
That would not be as effective as running the liquid through the CPU core.
For the cray2, that was running liquid through the CPU core.
Seen it in 1984 (Score:2)
Re: (Score:2)
Old joke (Score:2)
Re: (Score:2)
Re: Closed loop (Score:2)
Re: (Score:2)
Re: Closed loop (Score:1)
Mineral buildup was solved a loong time ago.
But morons kept replacing the water, as if it would "go bad"... replenishing the minerals and corrosive power.
The rest of us used distilled water and glycol. At least in 2005, when I tried it, before mainboard components could be water-cooled, and ruined $1500 worth of components. ;)
Active cooling? (Score:2)
Re: (Score:2)
You do realise that you water "cool" guys exist in a large part because you're able to move far more heat using a liquid medium than a heatpipe can right? Otherwise watercoolers would have heatpipes in them. But they don't because that would be stupid.
Now the goddam researchers are ... (Score:2)
... demonstrating.
Send in the unmarked military!