IBM Supercomputer Cooled With Hot Water

1sockchuck writes "IBM has deployed an innovative supercomputer cooled by hot water in a Zurich computer lab. The Aquasar supercomputer employs a chip-level liquid cooling system that can use water at temperatures as high as 60 degrees C (140 degrees F), and as a result consumes up to 40 percent less energy than a comparable system using room-level air-cooling. The system also uses waste heat to provide warmth to buildings, reducing Aquasar's carbon footprint even further."

Comments

Sooo

[binarylarry]

You could prepare soup while you supercompute?

Re:Sooo

[bsDaemon]

a soupercomputer?

Re:Sooo

[EdIII]

I would think it would soup or computer.

Saw a presentation on this last year...

[Saint Aardvark]

I was at LISA '09, and Dr. Bruno Michel (works for IBM, mentioned in the article) made a presentation on this work (or at least very, very similar work). You can see the presentation, or download the MP3, here:

http://www.usenix.org/event/lisa09/tech/tech.html#michel

Interesting talk, and well worth your time.

Re:Saw a presentation on this last year...

[Anonymous Coward]

Short answer...because they were engineered to that tolerance, and not beyond.

We could design chips that would run well at 80-100 degrees, but they would have to run slower and probably use larger transistors than current generations. The reason why all the chips run well at 60 degrees is because that's a reasonable temperature to be able to keep them at. They would run faster if we could keep them even cooler with practical approaches. You might have heard about "extreme overclockers" that use liquid nitrogen to get a desktop chip to run at 4-5 GHz. If it were practical and cost effective for everyone to cool their computers with liquid nitrogen, then they would all run faster, but you'd have someone on slashdot asking the questions "Why can't silicon/CMOS work reliably at room temperatures?".

There is a video

[Jarik C-Bol]

There is a video in the article, as well as a diagram that seems to explain how this works. (the long and short of it is, the hot water cools off quickly towards the lower atmospheric temperature (which allows passive coolers), but is cool enough to remove heat from the chips.

first?

Re:There is a video

[Jarik C-Bol]

replying to myself to explain better. the chips need to be run at 85 C, (185F) and the water is about 60C (140F) this means the water is cooler than the chips, and will remove heat from them, and then, as i said above, it dissipates that heat quickly because of its high temperature. (along the lines of that whole "hot water freezes faster" thing)

Re:There is a video

[Sulphur]

The temperature difference is higher, so the heat flow is more.

As for the frozen water: Hot water gets dissolved gas driven off and cold not. Cool both and the one with more solutes (the cold) gets frozen last.

Evidence of this: Hot tap that was not turned off at the mains snorts.

Re:There is a video

[TechyImmigrant]

>Evidence of this: Hot tap that was not turned off at the mains snorts.

My hot tap is not turned off at the mains and it has never snorted.

Re:There is a video

[jd]

I'm much more puzzled by what a hot water tap would snort. There can't be much that would give a lump of metal much of a buzz.

Re:There is a video

[jd]

Hot water doesn't freeze faster. However, water at 80'C will cool to 60'C much faster than water at 60'C will cool to 40'C, given standard atmospheric temperature and pressure for the ambient temperature of the room. The flow of heat from a hot medium to a cooler medium varies non-linearly with temperature. For example, as you approach the same temperature, the flow of heat approaches zero.

(In other words, if they piped through cold water which was heated to room temperature, a passive radiator would be useless.)

There is a drawback with hot water, though. The temperature gradient issue cuts both ways. As the temperature of the water approaches the temperature of the chips, the heat flow from the chips is reduced. Thus, water at 60'C will not draw off as much heat as water at 40'C, if the chips were to run at 80'C. You've got to balance this sort of approach fairly carefully.

I rather like the Cooling Tower approach (evaporative passive cooling). Basically, you blast the water through a nozzle that turns it into a fine mist. You collect the water that actually reaches the reservoir at the bottom and top it off. The drawback of this method is that it is somewhat bulkier than a radiator system. It is also not a closed system and therefore is a bit more expensive to run. On the other hand, evaporative cooling is much more effective than relying on simple heat flows, so you can get away with a lower temperature gradient at the cooling end. This, in turn, means you get a steeper temperature gradient for the chips, which means they're cooled much more effectively and can therefore be driven much harder without loss of reliability.

Re:There is a video

[Przepla]

Hot water doesn't freeze faster.

Sometimes, it does.

Re:There is a video

[jd]

If evaporation is considered a possible explanation, then the containers aren't sealed. If the containers aren't sealed and have equal volumes of water, then they have unequal masses of water. The specific heat is the amount of heat per unit mass required to raise the temperature by one degree Celsius. In order to prove that hot water can freeze faster, you must have an equal mass. Since radiation is a function of surface area, you must also have an equal volume. Therefore you must have sealed containers and unequal pressures. This is not the experiment described on Wikipedia.

However, it would be an extremely interesting experiment to perform. I'd actually suggest three closed containers (one with cold water, one with hot water and equal pressure, one with hot water and equal mass). I'd also suggest running thermocouples to the center of each container and plotting the temperature over time. This will eliminate all of the unknowns and variables not accounted for in the original experiment or in the Wikipedia write-up.

Regardless of what the results show, they will be quite interesting and useful for students starting on the topic of thermodynamics.

Re:There is a video

[Jarik C-Bol]

the explanation that i was given for hot water freezing faster (and i'll admit that i am not a hydrologist of whatever so work with me here) that hot water froze faster because the water molecules where in a more energetic state, which allowed them to assemble into crystalline structures more readily.
retrospectively, that does sort of sound like bullshit.

so i'll admit, the hot water example was a extremely bad one based on anecdotal evidence. But hey! my grandmother used anecdotal evidence all the time, and she lived to be... well she's still alive.

Re:There is a video

[jd]

Thermodynamics students would benefit from a correct understanding of heat transfer. If the model is faulty, then their calculations will be in error. If the counter-claims are faulty, knowing and understanding why will prevent them from going in messed-up directions. Extracting useful work is only possible (on any quantitative level) if you know what work can be usefully extracted.

Re:They should put the chips underneath

[Smallpond]

IBM is very good at making non-leaking water hoses. I wish Sears would license their technology.

Hypothermia in hot water

[Anonymous Coward]

Water is really an effective cooler even at what you might normally think of as quite high temps.

Reminds me that you can die of hypothermia even in tropical waters of 80 degrees if you are unfortunate enough to get trapped in such water for long enough.

taking a shower

[TrancePhreak]

"Honey, we ran out of hot water, could you put on some DOOM5 while computing all of pi?"

Lack of cooling water = overheated chips = ?

[mbstone]

If a lot of people take a shower all at once will this cause a network latency?