Tiny Bubbles Key to Cooling Crazy Hot CPUs 238
Smaz writes "With future CPUs expected to generate as much as four times the heat of today's processors, wicking away that heat remains one of the biggest engineering hurdles in the biz. Researchers at Purdue have developed a pumpless liquid-cooling system that removes nearly six times more heat than existing systems. The trick, it seems, is in the tiny bubbles. From the Science Blog."
Pumpless circulation (Score:4, Interesting)
Re:Pumpless circulation (Score:5, Informative)
Two terms to look up if your interested in this aspect of Heat Transfer and Fluid Flow would be subnucleate boiling and the departure from it. There is a balance between the amount of boiling and the amount of heat transfer. Not enough and you don't get many benifits... too much and the large bubbles that form on the channel walls effectively create a steam void that has a much higher specific heat then the fluid used for cooling... basically it is acting as an insulator preventing heat transfer into the fluid in the channel... a very bad thing [tm]. That is where departure from nucleate boiling comes in (this being the good thing) departure being where it starts getting bad very quickly.
Think pot of water for spaghetti before the water really starts boiling... Oh, and I apologize for my horendous spelling but you don't have to spell to run a nuclear reactor.
Re:Pumpless circulation (Score:3, Funny)
Note found at Chernobyl:
seam to haveing seeris probum with retacter. dun't sart teests
Re:Pumpless circulation (Score:5, Funny)
Very true, Homer. Very true.
Re:Pumpless circulation (Score:3, Informative)
Cooling ability of water alone is good.
Cooling ability of water with slight boiling is really good.
Cooling ability of steam is really bad (3 Mile Island comes to mind among other things).
Very fine line...
The trick is controlling the amount of boiling so that the steam collapses when it is stripped away from pipe surface.
If not.. I hope they have analyzed for the hot channel effect or even worse, flow reversal!!
I too was in nuclear power, and can't spell either
Re:Pumpless circulation (Score:2)
!!!
Does anyone else find this alarming?
Re:Pumpless circulation (Score:2)
It's highly conductive, liquid, and has a much larger heat capacity than water. Sure it's a poison, but this is a closed system. No leakage. So why not inject liquid mercury into these micro-channels instead of water?
Treehugger #1 (Score:4, Informative)
Re:Treehugger #1 (Score:2)
Re:Treehugger #1 (Score:3, Informative)
Because it conducts electricity? The cooling tubes are inside the CPU chip, so a leak would be somewhat problematic....
yeah (Score:3, Funny)
Re:yeah (Score:5, Interesting)
I'd love to submit an "Ask Slashdot" article on the making of bongs. I'm sure we'd see quite a few novel ideas from the MacGyver Smokers [moviewavs.com] out there...
Cavitation? (Score:5, Interesting)
Re:Cavitation? (Score:5, Interesting)
Re:Cavitation? (Score:5, Informative)
Re:Cavitation? (Score:5, Interesting)
What your parent reffered to was the formation of very tiny bubbles that quickly collapse and release microjets which are very damaging to surrounding surfaces.
Those tiny bubles also have the (generaly) unwanted property of always orienting themselves so as to send the microjet against the surface of contact, thus making the problem more severe and less unlikely to happen that it might sound in a first thought.
Those nasty microjets can do a lot of damage and are the reason why stainless steel helices of boats still get corroded.
In the case of the proposed cooling system, the surface of the channels might be attacked by the released microjets until perforation, since it is so thin.
Re:Cavitation? (Score:5, Informative)
Your explanation of microjets is good.
The parent post makes the mistake of identifying bubble formation with the cavitation damage, where as you point out, it is the bubble collapse that is the dangerous part.
Another important thing to note is that bubble collapse is more of a problem when there is a large disparity between the bubble pressure and the ambient liquid pressure. Lots of liquids, like beer, sustain CO_2 bubbles nicely for lengths of time, without the beer glasses sustaining lots of chipping damage from microjets. The pressure of the gases in beer bubbles can be higher than atmospheric pressure.
Under the ocean, however, where props rotate at high speed, the bubbles that are created have little more than water vapor in them (that's what cavitation is all about - causing the water pressure to drop below its vapor pressure). Those bubbles are highly unstable and short-lived.
Re:Cavitation? (Score:2)
Bubbles forming on a hot spot in a liquid that is significantly below its boiling point collapse in place. The expansion gives them a large cooling surface an allows the vapor to suddenly cool below the boiling point and recondense. It isn't until the liquid is superheating near the bubble formation site that the bubble continues to ex
Re:Cavitation? (Score:2)
Re:Cavitation? (Score:2, Interesting)
Here's my horrible analogy: the starting surface is like a indi race trace - very smooth. After cavitation, the road looks like the Brooklyn Queens Expressway (where the surface area of the potholes is greater than the surface area of flat roadway.)
Re:Cavitation? (Score:3, Funny)
No, no! It won't be the shock waves that reduces the life of the chip...rather, it will be the hard radiation from the resulting sonoluminescence and nuclear fusion [discover.com] that will undoubtedly occur.
Re:Cavitation? (Score:2, Informative)
From looking at the article, I don't think that there is any cavitation in these pumps.
Wow, who woulda thought... (Score:3, Funny)
Re:Wow, who woulda thought... (Score:3, Funny)
Great stuff!
Re:Wow, who woulda thought... (Score:2, Funny)
Re:Wow, who woulda thought... (Score:2, Funny)
He got his first name from his godfather and his last name from yo' mama.
And the next great innovation... (Score:2, Funny)
Yes but will they keep you from burning your unit (Score:2, Funny)
Laptop burns boffin's penis
November 22 2002
Doctors are warning that laptop computers may inflict a burn even through clothed skin, after the bizarre case of a Swedish scientist who scorched his penis and testicles while writing a report in his armchair.
The unnamed 50-year-old father of two had balanced the computer on his lap while he wrote the report at home, taking about an hour to do it, according to a letter published in the next issue of the British medical weekly The Lancet.
The f
Re:Yes but will they keep you from burning your un (Score:2, Informative)
No, they'll help it happen faster... No slow heat up of the bottom of the laptop - This heat pump is up to 6 times as efficient as the heat pipe. It'll just get the heat away from the cpu faster, no help in keeping it away from your unit.
To recap - No nude laptopping. It is not allowed.
Re:Yes but will they keep you from burning your un (Score:2)
I bet there were countless others that submitted it too, and given that I don't understand why it didn't make it? I'm not grousing, I'm just curious ...
Anybody else... (Score:2, Funny)
Re:Anybody else... (Score:2)
It's shagadelic!
Cooling - Lava Lamp - Random numbers (Score:3, Funny)
Clarification (Score:5, Informative)
It's misleading to generalize "existing miniature pumpless liquid-cooling systems" to "existing systems", as was done in the discussion header. At least, it made me think article was about a cooling solution six times better than *ALL* existing cooling systems. Of course, this leads one to question how good "existing miniature pumpless liquid-cooling systems" are...
Re:Clarification (Score:2)
And those do work pretty well.
Re:Clarification (Score:2)
so in the future... (Score:5, Funny)
darn, all have to get a new recipe book.
Cue the Don Ho Jokes... (Score:5, Funny)
Tiny Bubbles
Running WINE
Make me happy
Make my PC feel fine.
Tiny Bubbles
Make me warm no longer
With a feeling that I'm going to cool you
Till the end of time
So here's to the Boilermakers
And here's to Purdue
But mostly here's to a cooler CPU
Tiny Bubbles
Running WINE
Make me happy
Make my PC feel fine.
Groan (Score:3, Funny)
For all the non-Microsoft folks out there:
Tiny Bubbles,
...
Running Xine,
Make PC happy,
Make PC fine
(Cue the large beast swallowing the poster in a Monty-Pythonesque cartoon sequence.)
Aero Bar (Score:3, Funny)
DJCC
Guinness as cooling agent ? (Score:5, Funny)
So maybe these chips will be served with a Guinness cooling agent ?
A 500 year old cooling method can't be wrong !
I love my chips with Guinness !
Hic, arrrr
Re:Guinness as cooling agent ? (Score:2, Informative)
This brings me to my favorite rant... (Score:5, Interesting)
This seems like a nice technology to remove the heat from the CPU, but what I'm always wondering about is, where will the heat actually be dissipated into the environment? At some point, there has to be a heat exchanger where all this heat collected in the tiny bubbles is passed outside the unit. This is going to take a fair amount of space - one of these days we're going to see ads for heat exchangers that take up less space than the "standard" box available from Intel.
I'm looking forward to a Beowolf cluster not only performing amazing calculations but also heating the building it's in.
myke
Re:This brings me to my favorite rant... (Score:3, Insightful)
Sure you could link up your ventilation system to your PC, but that's just overkill.
Re:This brings me to my favorite rant... (Score:3, Insightful)
The PC cooling problem has become so ridiculous that some are resorting to using liquid cooling systems to alleviate some of the annoying fan noise modern PCs have. Others are underclocking their processors so they don't need as much fan cooling.
Chip manufacturers have made great strides in reducing the feature size on chips (down to 130 nm now, with 90nm coming soon), and reducing the operating voltage. Both of these measures greatly increase th
Re:This brings me to my favorite rant... (Score:2)
Re:This brings me to my favorite rant... (Score:3)
If I adjust the temp, my co-workers begin to hate me. Who wants to wear a jacket in the summer? What we need is a venting system to get heat away from the source. Imagine 200 PCs running in Arizona in the summer. Half the A/C is being used to offset the PCs.
If only it could be shipped nort
Heat your home (Score:2)
Or you could build a water heater/home server.
Interesting.. (Score:2)
Amazing! That's also the trick behind Dr Pepper!!
Just how do they make them so damn small?
Next Generation Cooling (Score:3, Interesting)
Now we know why Intel was so anxious to get their anti-overclocking technology working.
i call that this is going to be.. (Score:5, Funny)
yeah, had to say it and couldnt find it said with 1 sec search.
Tiny Scrubbing Bubbles... (Score:2)
We keep cooling so you don't have to.....
Throwback from some bubble advertisement in the 80's.
good analysis (Score:2, Informative)
I've known this all along (Score:3, Funny)
Laminar Flow layer (Score:5, Informative)
Re:Laminar Flow layer (Score:4, Informative)
Re:Laminar Flow layer (Score:2)
Re:Laminar Flow layer (Score:2)
thats when you apply a tetrionic field inducer and wait for the neutron radiation to build up. then you just use the coefficient of muons reactivuty to counter balance it all.
misread first line (Score:3, Funny)
I was going to agree... my t-bird 1.3ghz gets daamn hot.
Fish tanks have used these for years (Score:2, Interesting)
The hardware layout would need to be orientation independant for a laptop though.
Heat = power consumption = money (Score:3, Insightful)
Does anybody have any numbers on current and future power consumption, and what it would cost per year with current or future electricity prices to keep a computer turned on 24/7?
Re:Heat = power consumption = money (Score:2)
Re:Heat = power consumption = money (Score:2)
$.10/kwh=.0001 cents per watt per hour
365 * 24 = 8760 hours per year
8760 * 0.0001 = 87.6 cents per year per watt
something wrong (Score:4, Interesting)
-The chip needs to be at the boiling point of the liquid, maybe not a problem (freon anyone?).
-What happens when the CPU isn't pointing up? (e.g. on a motherboard in a standard case) Will it overheat because the bubbles don't "rise"?
Re:something wrong (Score:2)
Maybe this "tower" could be a cone shape, so that bubbles a
Of course it came from Purdue (Score:3, Funny)
What happens when you tip the thing over? (Score:2, Interesting)
Re:What happens when you tip the thing over? (Score:2, Interesting)
Picture (Score:5, Informative)
Re:Picture (Score:2)
Translation: 95% of
As for the other 5%:
2% skimmed it and didn't see the Crazy Hot Heat as promised and gave up on the picture. Here your work was definitely appreciated.
another 2% understands the Crazy Hot Science Geek lingo and proceeds to write insightful and informative comments on the subject. Here your work goes unappreciated.
The rest trol
Re:Picture (Score:2)
Man.. imagine how big of screen my laptop would have if the implemented one of those devices!
So when can we stop wasting heat? (Score:2, Interesting)
Future CPUs will use LESS power (Score:3, Interesting)
I'm sure the average PC in the future is going to be using LESS power than today.
Re:Future CPUs will use LESS power (Score:2, Informative)
The current emphasis on low power CPU's isn't an effort to reverse the power consumption trend, merely to slow it down. In most cases, power consumption offsets performance. Historically, designers have almost always favored performance, resulting in power consumption varying roughly with clock speed (P~af^2) squared for the same family of chip. Current efforts are to bring that closer to a linear relationship (P~af). However, even in this "ideal" relationship, faster chips will use more power (and whil
Different approach from HP (Score:3, Informative)
The article is here [economist.com] but unfortunatly it's pay per wiew.
The article also mentioned that future (within 2005) CPU's will generate five to ten times more heat.
The feedback mechanism inside this inkjet head included a sensor so the squirt can be directed to the hottest areas. Really cool. No phun intended.
Re:Different approach from HP (Score:3, Funny)
Let me guess: they'll sell these high-end servers for only $50. The catch is that they'll constantly consume cooling fluid from insanely priced single-use proprietary HP cartridges. What's worse, the server will come only with a half-filled cartridge.
But can they scrub? (Score:3, Funny)
Then my PC will be heat AND dust free! Less work for Mom!
Why must the manufacturers make even hotter CPUs ? (Score:2, Insightful)
Isn't it time for lower power processors? (Score:3, Insightful)
Re:Isn't it time for lower power processors? (Score:2)
Stop using fish! (Score:4, Funny)
That's the problem with today's technology. We keep using Fish in our hardware. No wonder the experts predicted that the smaller the channel, the less heat that would be dissipated (paraphrasing). The fish they were using would not be able to fit though the small channels, thus causing the channel to be blocked!
Re:Stop using fish! (Score:2)
I wonder if Mexicans would be so successful in cooling silicon.
efficiency question... (Score:3, Interesting)
Every comparison in the article was with current liquid systems. How much more efficient would this be than the heatsink/fan cooling my Athlon?
Solid conductors (Score:5, Interesting)
Want silent cooling??? Design a case where the healt-sink goes from the processor, to the outer-shell of the case... Presto, no more restricted airflow, and no fans at all.
Convection works well when there is a large surface area (unlike current CPU heatsinks), and there is little impediment to airflow (unlike current systems).
In fact, you could have some incredibly hot systems if you designed a case with a large, EXTERNAL, healtsink, mounted so the top is flush with the case. It could look like a grill on the top of your case instead of a flat piece of metal, but be connected to the CPU with copper/aluminum.
I've always been wondering why nobody designs computers that conduct the CPU heat outside the case. Anybody have some ideas?
Re:Solid conductors (Score:3, Informative)
Tiny Bubbles... (Score:2)
This explains exploding control panels (Score:4, Funny)
Cue the CPU fart jokes! (Score:2)
Heat sucks (Score:4, Insightful)
The key question (Score:2)
And, if I may ask, what is the performance of existing miniature pumpless liquid-cooling systems. I have not seen any in the store lately. Do they perform as well as pump-driven systems (probably not)? Do they perform on par even with fans (maybe not)?
Tor
Why not advanced SMP? (Score:2)
I would think that a decent chipset which good inter CPU communication could at least rival say 350% of the same system in a single CPU config. Also wouldn't this just dispearse the heat more?
Then again I could b
Heat pipes (Score:3, Interesting)
Here's an example:
http://www.swales.com/products/heatpipe
New CPU architectures needed (Score:2, Interesting)
New architectures are needed that can do a ton of work per clock cycle. Then, clockspeeds can be r
Cost of electricity.. (Score:3, Interesting)
The articles states:
Innovative cooling systems will be needed in about three years for personal computers expected to contain microprocessor chips that will generate four times more heat than chips in current computers. Whereas current high-performance chips generate about 75 watts per square centimeter, chips in the near future will generate more than 300 watts per square centimeter, Mudawar said.
Who can afford the electric bill to run such machines in their homes? I already stress over the few rooms in my house where I use 100 watt light bulbs instead of 60 or 75 watt bulbs. Can you imagine hooking up your shiney new PC in 2006, then getting an $800 electric bill the next month? Man..
I guess powering down your system when not in use will become more common.
Anyone think of the wasted energy? (Score:3, Insightful)
This is the kind of thing that just outrages me, I think what should be perfected are efforts like the VIA CPU's or the Crusoe (ugh). This brute force mentality in CPU's and Video cards is getting ridiculous. Things need to change in a big way, and I hope that they start soon because I'm not buying or running a 1500 watt powersupply 24/7. I don't care how many FPS it can push in Quake III, hell California alone would be under blackout conditions forever if we start seeing CPU's like this.
Re:Imposible to read (Score:3, Funny)
Try this special secret Flash advertisement blocking technique:
# rm /usr/lib/mozilla/plugins/libflashplayer.so
I have found it is capable of stopping all flash advertisements before they even load.
Remeber, it is a secret. So please don't tell anyone.
Re:Imposible to read (Score:2, Informative)
Re:Imposible to read (Score:2)
Re:note who funded the research (Score:3, Insightful)
Re:note who funded the research (Score:2, Offtopic)
Your implication that wellfare is the only other area for spending money (or even th