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Hardware

Liquid Nitrogen Beats Air Cooling (Again) 199

Posted by Roblimo from the don't-try-this-at-home dept.
joe094287523459087 writes "some guys used liquid nitrogen cooling via a cardboard tube to get a 20,000 3D Mark score. you can see the frost forming on everything - wouldn't the moisture from the condensation kill the board?" The Muropaketti guys had already done this with their microprocessor. Apparently the next step was to speed up their graphics card to match.
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Liquid Nitrogen Beats Air Cooling (Again) More

Liquid Nitrogen Beats Air Cooling (Again)

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  • Fabulous (Score:4, Funny)

    by FreeLinux ( 555387 ) on Sunday October 20, 2002 @11:01AM (#4489665)
    I'm sure the soldered joints have no problem at all with the MASSIVE and abrupt temperature changes here.

    When can we expect this on fuel cell powered laptops?

  • Not necessarily, if it's -196 C (Score:5, Interesting)

    by koko775 ( 617640 ) on Sunday October 20, 2002 @11:02AM (#4489667)
    wouldn't any condesnsation freeze before it could short the electronics?

  • somebody beat him to it (Score:5, Interesting)

    by Anonymous Coward on Sunday October 20, 2002 @11:06AM (#4489686)

    What's so special about him getting 20372 by overclocking his P4 to 3916 MHz?

    The article has a picture [muropaketti.com] showing that someone got 21504 by overclocking to 3998 MHz -- nine days earlier.

  • mostly tiny ice crystals from the fast cooling (Score:3, Interesting)

    by jo_ham ( 604554 ) <joham999 AT gmail DOT com> on Sunday October 20, 2002 @11:07AM (#4489687)
    The boiling point of nitrogen is miles below the freezing point of water, so in the immediate vicinity you'd have some fast chilling and ice crystals. I'd be more worried about liquid condensation further away from the cpu, if it lowered the internal temperature of the case for example.

    Unless they're venting vast quantites of boiling nitrogen into there though, it shouldn't be too bad. Plenty of hydrophillic stuff ariund should deal with that. A few sugar cubes in there, or some conc. sulphuric acid maybe!

  • Not the sharpest pencils... (Score:3, Insightful)

    by Pedrito ( 94783 ) on Sunday October 20, 2002 @11:07AM (#4489688)
    Is it me, or is that guy pouring liquid nitrogen with his bare hands? Is he aware of the danger of getting that stuff on his hands?

    • Re:Not the sharpest pencils... (Score:5, Interesting)

      by bjschrock ( 557973 ) <bschrock@@@gmail...com> on Sunday October 20, 2002 @11:13AM (#4489706)
      Actually, if you touch liquid nitrogen for just a short amount of time, you won't hurt yourself. The heat from your hand vaporizes the liquid nitrogen that actually touches you, so you have a small air pocket between you and the liquid nitrogen... of course, if you hold it for more than a fraction of a second, it won't feel too good. One of the professors here actually poured some liquid nitrogen in his mouth and spit it on the wall during one of my classes, and he did it quickly enough not to hurt himself.
      • One of the professors here actually poured some liquid nitrogen in his mouth

        And people complain about Jackass and Beavis & Butthead setting a bad example for our children?

      • Heh, yup. I had to watch a friend in 4th year physics dunk his fingers into and out-of liquid nitrogen really fast a few times before I was brave enough to try it myself.

        As advertised, the flash-boiled liquid nitrogen insulates your fingers for a fraction of a second. You can't keep doing it though, lest your tissue cool down too much, and who knows *exactly* how slow/fast you can do it without injury, and no-one was willing to try and find out :)
      • I went to smart camp [uncc.edu] when i was a youth, and in my physics class we spent an entire day playing with liquid nitrogen. You can actually hold it in your hand for quite awhile, provided you keep your hand open wide enough that your palm doesn't crease. As long as the LN doesn't get trapped between two folds of skin, you will be fine. Ditto for your mouth. You can hold a fair amount in your mouth, under your tounge with your tounge up and back. If you keep air flowing across it, you look like you're breathing smoke. When you spit it out, any remaining evaporates almost instantly.

        We spent hours playing like this, and of the 20 of us in the class, not one was injured.

      • even more fun is using liquid nitrogen to freeze natural gas or propane. I remember having some great fun using a bunsen burner hose and bubbling the gas through liquid nitrogen to cause the natural gas to become liquid. After we had about half a cup of liquid natural gas, we went into a dark hallway, lit it on fire and poured it out. It was pretty neat, it looked like liquid flames rolling across the floor and up the walls where it hit. Recreating the expirement later, I managed to get some on my jeans..however, after a second or so the liquid burned off and there was no burning on my jeans (I assume it is similar to alcohol and the gas is what actually burns...).

        Just proves that you can play with fire and liquid nitrogen at the same time.
    • There isn't much danger if you get it on dry skin; it will just harmlessly bead up and roll off. When people wear gloves, it's mostly to protect themselves in case some glass container breaks. However, if it soaks through clothing or if you take it internally, it can be dangerous.
    • Scalding hot coffee has a similar effect, and yet I pour that straight from the pot every morning - without gloves! He's not exactly going to soak his hand in the stuff, and a small amount will just evaporate off of the skin. Coffee actually is more dangerous to a certain extent....
    • It's not all that dangerous to work with. Certainly if you dunked your hands in a quantity of it, you could do some seriously serious damage..... but even if you spash some over your hand, it won't do much, especially if they are dry. You can stick a blob of it in your palm and carry it around even... just by swirling it a little. The lN2 that comes in contact with your skin vaporizes instantly, forming a gas layer between the liquid and your skin...

      Gloves worn during these experiments I think are more because of the other things that might get really cold while working with the lN2, or breakable...
    • No danger what so ever. In my first year (university) Physics lab, we got to play with some Liquid Nitrogen. I held my fingers in it up to the first knuckle (would have been deeper, but we just had small styrofoam cups) for at least 5-10 seconds. The Nitrogen boils around your warm fingers for a while, before they start cooling down enough for the liquid to come in contact.
      Even if that happened, it would take a while longer before you'd be in danger of loosing your fingers. You might suffer from some blistering or frost bite, but that would heal.
      Liquid Nitrogen is actually used in direct contact with skin as a treatment for warts. It's not really that dangerous.
  • Ok, so the Radeon has frost over most of its circuits. Is that dangerous for the said card? frost tends to melt into ... well liquid right?
    I must be missing something, if someone could please fill me in...

  • What's the point? (Score:2, Offtopic)

    by _avs_007 ( 459738 )
    So you can some awesome performance. What's the point? Lets say the guy does some UT testing and gets dick hardening results. But isn't that useless if when you're playing the game, and:

    1.) The frost/condensation shorts out the board
    2.) You run out of liquid nitrogen, and the board fries itself, locking up the game.

    There is nothing like playing UT while worrying about filling up the liquid nitrogen. With my luck, I'd end up accidently pouring the liquid nitrogen directly on the board, causing it to fiercly boil, and I'd drop the dewar flask and get the shit all over my hands.

    Besides, the blazing speed of the graphics will probably do nothing for me, so long as I have to deal with flaky lag on my broadband connection.
    • These guys are obviously just doing it for shits and giggles. The setup they have, without overclocking, should be far more than enough to play any current game at higher than acceptable framerates with all the options turned on, including FSAA.

      Is there any reason? Nope. Looks like fun though. If I had the cash to waste on stuff like that, I probably would.
      • Is there any reason? Nope. Looks like fun though.

        Looks like they're trying to get to the number one position on the MadOnion 3dmark chart. This time they made it to second place. Next time maybe they'll break the record. Yay for team Finland!

    • Re:What's the point? (Score:5, Funny)

      by romco ( 61131 ) on Sunday October 20, 2002 @11:20AM (#4489735) Homepage
      "...Lets say the guy does some UT testing and gets dick hardening results."

      That would mean he is putting the nitrogen in the wrong place....
    • That LN will take a while to evaporate once the container it is in cools down sufficiently. Physicists use cold traps powered by LN all the time. In fact, a friend of mine built a cyclotron that uses a 40 Amp magnet and he cools it with LN. He checks on it daily. It's pretty effective stuff.
    • To add insult to injury, not only are their methods totally impractical, but they don't even make a contribution to "science". Intel will release consumer chips that surpass that clockspeed in 6 months, anyway. Without ludicrous cooling systems that require liquid nitrogen.

    • Re:What's the point? (Score:4, Interesting)

      by Salsaman ( 141471 ) on Sunday October 20, 2002 @12:05PM (#4489892) Homepage
      Yeah I can see how this is technically cool, but you could just wait a few months and probably buy a 4GHz P4 off the shelf anyway.

      I mean Moore's law still trumps overclocking any day.

  • Limiting factor (Score:5, Interesting)

    by Paladin128 ( 203968 ) <aaron&traas,org> on Sunday October 20, 2002 @11:12AM (#4489700) Homepage
    The limiting factor in the performance of modern GPU's seems to be memory bandwidth. They were able to overclock the GPU itself a good bit, but not much on the video RAM.

    We really need to see more memory bandwidth saving technology on GPU's. ATI pushed ahead a lot of cool things (early Z, occlusion culling, Z-compression, fast Z-clear), but it's not far enough. The Kyro/Dreamcast use tile-based deferred rendering rather than immediate mode, and the GameCube's GPU (designed by ArtX, which is now a owned by ATI) uses a 2 MB on-chip Z-buffer cache which alleviates the need to go to video memory every time they want to do a Z-test (which is typically at least once per pixel). Given, the Cube doesn't ever have to deal with a frame buffer bigger than 720x480, so a fixed size Z-cache is much more useful there.

    On another note, I'd really like to see support for geometry amplification schemes (n-patch tesselation, displacement mapping, etc.) that work properly with stencil-buffer volume shadows.
    • I want to know why I can't put standard DDR memory on my video card. Why does a video card cost soooo much, just because of 64MB of memory, when memory prices are hitting the floor, even with DDR?

  • Liquid N colder than air.. wow! (Score:5, Funny)

    by verch ( 12834 ) on Sunday October 20, 2002 @11:14AM (#4489707)
    I've been doing some experimenting myself and I'm almost ready to post my 'steel is stronger than cardboard' article. Who would have guessed?

    This is cool in some horribly over the top manner, but I think the last cooling using liquid nitrogen story a few months back covered it.

  • Liquid Nitrogen Beats Air Cooling (Again) (Score:5, Interesting)

    by SuperDuG ( 134989 ) <<kt.celce> <ta> <eb>> on Sunday October 20, 2002 @11:14AM (#4489712) Homepage Journal
    Hehehehe, DUH :-)

    That aside, Liquid Nitrogen might be a bit of overkill here. When properly coated, I'm sure the parts are safe from the damaging effecets of melting, but everyone needs to remember one thing, heat is the enemy, it's obvious that it would take quite a bit to get too cold.

    Obviously there isn't a future in Liquid Nitrogen cooled computers, but take the idea back from the "weird science" to the new liquid/radiator idea. I do believe silent machines running cooler with liquid cooling, will become a new trend.

    Lastly, why does everyone brag about their 3DMark scores? If you suck at gaming the extra pixels sure ain't gunna help ya.

    • When properly coated, I'm sure the parts are safe from the damaging effecets [sic] of melting, but everyone needs to remember one thing, heat is the enemy, it's obvious that it would take quite a bit to get too cold.
      Melting is not the danger here. At high temperatures, the dopants used to make regions of silicon p-doped and n-doped (which make the transistors on your CPU which do the computing) start diffusing out of the regions they're supposed to be into the regions they shouldn't be. Enough of that happens, and your many-transistor CPU becomes one large, expensive resistor. Incidentally, I think a similar problem delayed the use of copper interconnects--the copper would diffuse into the silicon and poison the transistors, so copper couldn't be used until IBM found a way to prevent that from happening.

      As far as being too cold--as long as no thermal shocks are involved, I don't think there's such thing as too cold. I look forward to /. stories about liquid helium cooling and the like... ;-)
      • I don't think there's such thing as too cold.
        well...if you cooled the system enough, something in there would probably start superconducting, and while SC is very useful if you've planned for it, it could really screw things up if you hadn't (i.e. if your copper substrate suddenly loses all resistivity, that's gonna mess up your processor).
    • Obviously there isn't a future in Liquid Nitrogen cooled computers,

  • Liquid Nitrogen Beats Air Cooling (Score:5, Funny)

    by Anonymous Coward on Sunday October 20, 2002 @11:17AM (#4489727)
    No shit Sherlock.

  • Next Step for these guys... (Score:4, Interesting)

    by MarvinMouse ( 323641 ) on Sunday October 20, 2002 @11:17AM (#4489729) Homepage Journal
    Build a compressor/cooler.

    If you could do it right, and can afford the proper parts to build it. Create a high-power compressor, and have it pipe super-cooled fluids continually through both processors. Therefore, you don't have to pour/buy liquid nitrogen everytime you want these results.

    The problem is that it costs a lot and is quite difficult to build a fast high-power compressor/cooler. If you guys can accomplish this, then I'll be impressed. Pouring liquid nitrogen onto stuff to keep it cool isn't really that exciting/impressive in the long run, since it is far to manual, and doesn't require much thought to come up with the idea.

    I am curious though, does anyone know of more fancy coolers for the processor that work impressively but don't require constant manual addition of coolant?
    • I'm pretty sure that real LN2 cooling systems (i.e. not a cardboard tube :-p) use a recirculating arrangement, so a single resevoir of LN2 is used to cool the chip. You can use a compressor to rechill it, or there are other methods. Personally, my favorite method of cooling is the Peltier effect. [abc.net.au] Basically, a voltage applied across a loop of two dissimilar materials will create a temperature gradient, i.e. one junction will get hot and the other will get cold. The result is a solid-state cooler with no moving parts that you could probably build on chip. The drawbacks are that Peltier coolers aren't super powerful, but to someone who is interested in unusual physical phenomena, that doesn't diminish their coolness factor. (no pun intended)
    • I'd imagine you'd probably need to put the whole computer into a vacuum chamber or something which removes humidity from the air, because after a while the frost buildup would be tremendous, and you'd have to occasionally defrost your computer, like we used to do with freezers =)

  • 1/2 the 3dmark tests not shown. (Score:4, Informative)

    by BrookHarty ( 9119 ) on Sunday October 20, 2002 @11:18AM (#4489730) Journal
    Checking out his 3dMark [madonion.com] and you notice, fillrate, poly count, shader, spride speeds are missing. Also only 4x AGP, be nice to also see 8x AGP enabled, his motherboard might not support it yet.

    His ATI driver is also 6.13.10.6159, he should upgrade to 6193, major performance increase. You can get it over at rage3d.com [rage3d.com]

    Impressive thou, Double my 3DMark [madonion.com] on a plain AMD 1800 with a ATI 9700.
  • If these people are so serious about verclocking and cooling the board, why didn't they devise some sort of automated liquid N2 delivery mechanism. The guy is pouring the N2 with his bare hands! Any info on the cost per minute?
  • Looks like an experiment in freezing duct tape ....

  • Avoiding condensation (Score:3, Interesting)

    by XNormal ( 8617 ) on Sunday October 20, 2002 @11:25AM (#4489752) Homepage
    Run the whole thing in an improvised glovebox filled with dry nitrogen gas at slightly higher than ambient pressure. Boiling liquid nitrogen results in large quantities of totally dry nitrogen gas.

    Now the only problem remaining is how to avoid condensation on the glovebox itself so you can see what's going on inside :-)

  • LN2 and condensation (Score:5, Interesting)

    by Idarubicin ( 579475 ) on Sunday October 20, 2002 @11:31AM (#4489764) Journal
    wouldn't the moisture from the condensation kill the board?

    Well--eventually, maybe. But what they've build is essentially the back half of a water distillation system. The water that condenses out of the air will be very pure, and have a very low conductivity. (The resistance of a 1 cm path through ultrapure water is on the order of 18 meg--that's ohms, not byes--so it probably conducts no more electricity than the plastic of the board.)

    Yes, the condensate will eventually pick up contaminants, and at the edges of the cooled region where liquid water is free to flow you're likely to have problems. The solution would be to keep the entire mainboard in a dry environment. Seal it in a box with only an inlet for LN2. The little bit of water in the box will condense out (on the N2 fill pipe rather than the board if you remove a bit of insulation) and as the LN2 boils off, the box will be filled with dry, inert nitrogen. As an added bonus, this will help suppress fires.

    • The water that condenses out of the air will be very pure, and have a very low conductivity.

      I'll second that...

      One of the most amazing trade show booth demos I've ever seen was a water distillation system. They had computer monitors running a demo while under water. I know the why and how, but still, just plain unnerving to see high voltage stuff working like it was dry.
    • ...and as the LN2 boils off, the box will be filled with dry, inert nitrogen. As an added bonus, this will help suppress fires.

      I'd be careful about something condensing into the liquid nitrogen as it boils off. Like oxygen. Liquid oxygen may start to get concentrated over time into the mix and create an interesting condition known as rapid oxidation. Some people might call it combusion. Others may describe it as an spectacular explosion.

      If liquid oxygen can set a highway on fire (to bad that famous tanker scene in Terminator wasn't O2, not N2,) imagine what it can do to a computer in the privacy of your own home.
      • I'd be careful about something condensing into the liquid nitrogen as it boils off. Like oxygen.

        Worth noting, definitely--but not likely to be a problem. As long as LN2 is flowing in to the box, and the box is not perfectly sealed any oxygen that was inside when the box was closed will be slowly flushed out. I imagine that most hacks assembled from /. posts aren't quite airtight, so the concentration of oxygen in the gas mix will decay exponentially with time.

        Also, since only the GPU and CPU are directly cooled with LN2, the rest of the board will stay warmer, limiting problems with O2 condensation.

  • Captain Obvious on Line 1... (Score:5, Funny)

    by Anonymous Coward on Sunday October 20, 2002 @11:38AM (#4489791)
    Liquid Nitrogen Beats Air Cooling (Again)

    In related news:
    Ice is colder than Steam
    Touching hot things will burn you
    You can skate on ice
    Lots of fire will make things melt
    The speed of light is very fast
  • That's not frost you see, but chip outlines silkscreened onto the board. These are used by manufacturers to ease asssembly (eg, capacitor C32 goes here, resistor R98 goes here, chip IC42 goes here, etc.).
    • I don't know about you, but this [muropaketti.com] (9th image from the top) sure looks like frost to me.

  • Space Cooling... (Score:3, Interesting)

    by WeaponOfChoice ( 615003 ) on Sunday October 20, 2002 @11:52AM (#4489838) Homepage
    Have the guys on the ISS (or indeed any space mission/station) ever used the 'cold hard vacuum' of space to get their systems running cool and fast. You don't have the problem of condensation, you could make the sink a great big copper array (being very, very sure to always keep it out of the sun) and you'd enjoy even better performance (it's only about 3 Kelvin out there...).
    I guess you'd run into problems with cosmic radiation - but nothing a good dose of shielding wouldn't fix. Placement would also be an issue, couldn't just pin it to the back of the station...

    Anyone know of any experiments along those lines?

    • Re:Space Cooling... (Score:3, Informative)

      by benh57 ( 525452 )
      Have the guys on the ISS (or indeed any space mission/station) ever used the 'cold hard vacuum' of space to get their systems running cool and fast.

      Yes, they do. They aren't experiments, they are in fact how the space station works. On the last mission they brought up 3 more ammonia radiators. [nasa.gov]

      These work by taking water which runs past the electronics, exchanging that heat to liquid ammonia, which out the truss, and through these huge metal radiators which then radiate the heat to space. They have to use ammonia because the water would just freeze if it went through the external radiators.
      More space station info... [nasa.gov]

    • The radiator would have to be enormous to get cooling levels that one approaches on earth (this being of course, that heat transfers well into molecular mixes such as the atmosphere. Since space is a vacuum the only method of losing heat is radiation)

      I don't have any good hard figures on this, but it seems to me that if you want to cool something down that near absolute zero, you're going to need something a bit more active than a big radiator. In labs here on earth that sort of cooling can only be done on a nanoscopic level, generally using lasers to slow down atoms.

    • The last word means that convection and conduction are no longer options for getting rid of heat.

      Vacuum happens to be an excellent insulator...

      And when the station is in direct sunlight it heats up VERY quickly. You can expect temperature swings for something in orbit to go from freezing cold to burning hot - Often in the course of a few minutes.

      I was involved at school in designing a small satellite (See cubesat.org for a general description of this class of satellite) - I was (fortunately) handling the radio board, and wasn't one of the thermal guys. I felt sorry for them...

      During dark times, the satellite had to have small heaters to keep the batteries from freezing.

      20-30 minutes later in the orbit, the satellite's problem would be overheating.
    • He has some measure of "protection" from the Liedenfrost effect -- if cold N2 gets on his relatively hot hand, it'll flash-boil and create a thin cushion of gaseous N2 that should protect his hand from the liquid to some degree. This can be demonstrated by a competent professional by pouring a small drop into the palm of the hand.

      Now, if his fingers slipped and the cup of N2 fell over his hand, he'd be out of luck... Wearing gloves in that case isn't enough protection, because the liquid will just run down the glove, under the cuff of the shirt, onto the arm. The best thing to do is manipulate the N2 dewar with a long pair of tongs...

      People have done dumber things before, like dousing their head in alcohol (to kill lice) then lighting up a cigarette...

  • Moisture (Score:4, Informative)

    by gweihir ( 88907 ) on Sunday October 20, 2002 @12:23PM (#4489962)
    The moisture forming on the board is distilled water. It is about as clean as possible and has a very low electrical conductivity. It is mildly corrosive, but given that the only exposed metal surfaces are tin or gold, that is not a problem if the exposure is not too long.

    I would think that you need to immerse a board in distilled water for some weeks or months to get actual damage. Fans, HDDs and other moving parts are a different story.
  • OK, maybe i'm missing something, but at that temperature, wouldn't some parts be smaller than they should be and some larger? I'm pretty sure that the coefficient of thermal expansion of plastic != that of silicon != that of copper. And besides, if you consider silicon, its resistivity is negative, meaning it generally increases with temperature increase. (it may be positive, depending on how your teacher taught it.) So although cooling it would result in higher conductivity for the copper, wouldn't that put the silicon to sleep, effectively?
  • It would appear that muropaketti.com's server is using the same technology to avoid the slashdotting meltdown that I fully expected.

    I can hear it talkin' smack right now - "Bring it on you /.'ers. Brrrr. Is that all you've got? Fsck it's cold in here. All your hits are belong to us. God Dammit!!!, when I was shipped here from California I knew Finland was cold, but this is just fscking ridiculous."

  • 21504 3DMarks (Score:3, Informative)

    by hoyhoy42 ( 531811 ) on Sunday October 20, 2002 @12:40PM (#4490022) Homepage
    It would suck to have wasted all of that time with ln2 and still not have the top score. http://holicho.lib.net/top/020912/020912.htm http://gamershq.madonion.com/hardware/halloffame/

  • Liquid cooling (Score:3, Interesting)

    by Alcoholist ( 160427 ) on Sunday October 20, 2002 @01:05PM (#4490138) Homepage
    The next step is liquid helium I think.


    It's really, really cold. [imagetechnology.net]

    • Yes, but if it gets too cold and goes superfluid then it'll start creeping up and out of its container - perhaps the guy in the photo had better start wearing his themal gloves if he tries He cooling.

  • Environmental Limits? (Score:3, Informative)

    by kidlinux ( 2550 ) <<ten.xobecaps> <ta> <ekud>> on Sunday October 20, 2002 @01:27PM (#4490236) Homepage
    Wouldn't what they're doing exceed environmental specifications for the chips?
    I looked around ati.com and intel.com, but couldn't find any specifications on what the upper and lower bounds are as far as temerpature is concerned. I recall seeing in most product specifications for electronic devices temperature limits, and I thought the lower was usually around -15 degrees celcius.
    Or does the temperature of the chips ever get that low? Do they hit some kind of equilibrium that keeps them from reaching their lower limit?

  • In Other News (Score:3, Funny)

    by Geeyzus ( 99967 ) <mark_madej@@@yahoo...com> on Sunday October 20, 2002 @01:30PM (#4490255)
    Shoes beat top barefoot running speed

    Telephone more effective than tin can and string

    Umbrella proven more effective at staying dry than dodging raindrops

    Mark

  • Damn it (Score:2, Informative)

    by aufecht ( 163961 )
    And I just got a Pentium II 233MMX IBM ThinkPad and was hella excited about that. But seriously, why doesn't someone try out these experiments on a Linux system? I'd be curious to see the differences in performance. I'd do it myself, but as I noted earlier I just got a PII 233 Thinkpad so we know what my financial situation is.

  • Thermal shock (Score:5, Informative)

    by panurge ( 573432 ) on Sunday October 20, 2002 @02:00PM (#4490397)
    Someone mentioned this. Forget the solder joints for a moment (though the pure tin used on some boards now will actually crumble after a time at liquid nitrogen temperatures) the contraction of the case of the CPU will put stress on the pins, and the temperature differential between top and bottom of the case will put stress on the die joints.
    Also, if I remember rightly, the actual drain currents of the transistors goes UP because the resistance is going down (which is why you can overclock, of course.)Although the lowered temperature means the tracks will not be damaged, there may be other effects of the increased current density in longer term degradation of the die. If there is track necking anywhere, this might be a potential failure point.
    You might also expect damage to the epoxy cladding of the graphics chips, as the contraction pulls the epoxy away from the filler. This could result in the epoxy eventually becoming porous and the system failing due to moisture penetrating the cladding, just like 6502s etc. used to fail before anyone realised that glass fibre filler could wick water in to the die.

    The answer is to follow Seymour Cray and sink the entire system in cold fluorinert, using the total loss nitrogen system, or much cheaper dry ice, to keep the temperature at a sensible -45C or so. But that wouldn't be nearly so spectacular, would it?

    This is all a bit like our local hot rodders who can't safely make it to the next town and back for fear the engine will blow up on them. Even so, it would be nice if Intel would release some of the data they doubtless keep on this sort of thing.

  • Watch a Thunderbird burn to death (Score:5, Interesting)

    by ma++i+ude ( 580592 ) on Sunday October 20, 2002 @02:10PM (#4490442) Homepage
    Kind of to go with this, I found a (Finnish, sorry, but you can still look at the purdy pictures) page [mikrobitti.fi] that has some interesting avi clips. These people got an infrared camera [infradex.com] to do a few DivX clips on how the heat is distributed across the components. I like the first one best; they actually destroy an uncooled 1.4GHz Athlon Thunderbird. The CPU temperature rises to 300 deg C in about six seconds!
    • To get accurate temperature info from thermal images, you need to paint everything you're imaging. (Usually black - Get it as close to an ideal black body as possible). Otherwise, some colors are better radiators than others and will appear warmer on the camera at the same temperature.

      That said, even unpainted, a thermal camera can tell you, "Something is really heating up quickly... That isn't right..."

  • Capacitors usely go bye bye (Score:3, Interesting)

    by The Moving Shadow ( 603653 ) on Sunday October 20, 2002 @02:12PM (#4490448)
    When using rigour ways of cooling like just pouring LN over your board usually the capacitors give out first. Since they always attract moisture like crazy (remember those old radio's used to die because the capacitors were leaking electricity due to moisture in them?) there's always a small ammount of moisture in them. Now you don't want to have icecrystals forming in there. But still it's amazing what those boards can take. I have seen an old BX motherboard bent at an odd angle by someone pouring LN over it and still working. (Due to the immense temperature differences in the upper and lower side of the board the upperside folds inwards as material shrinks when the temperate is decreased) I guess the soldering is really done well. The same thing must have been happening at this chip btw. The underside of the GPU must have been warmer (a lot warmer) than the upperside so i don't want to even think about the massive ammount of material stress going in. ;) Well.... just keep up tweaking those GPU's and CPU's, it's always fun for us to watch.
  • but it seems like there should be some sustainable way of acheiving this kind of performance from these processors... could better cooling be acheived by increasing the pressure? anyone know how many atmospheres of pressure a P4 can handle?
  • There are plenty of reasons why this would not have worked.

    1) The specific heat of LN2 is much lower than water. This means that although you can get it cooler, you might not be able to get away enough heat to make a difference, or it might form a vapor barrier that prevents the LN2 for cooling efficiently. My guess would have been that you needed to actively pump it or agitate it. In fact, you probably can get quite a bit more cooling this way. If you've ever pour LN2 on your hand, you know that it doesn't really do very much (unless you cup your hand). Try this with boiling water and see if it hurts or not.

    2) Since none of these components were designed to withstand low temperatures, there's a chance that something could have cracked. If there was something that had a vastly thermal expansion coefficient in the packaging and/or became very brittle (e.g. plastic), it could have just split open. Apparently that's not a big problem either. My bet is that they cooled it down pretty slowly before they turned it on.

    I think the condensation issue is not as bad as one might think. It takes quite a bit of ions in order for water to become very conductive. It might be worthwhile to rinse your board in distilled water before trying this, but you probably don't have to bother. Just don't pour any salt on your board and it should be OK.

  • It's all about the home field advantage... (Score:3, Funny)

    by Junior J. Junior III ( 192702 ) on Sunday October 20, 2002 @05:05PM (#4491207) Homepage
    Just wait till they hold the air cooling part of the contest on Neptune. Liquid Nitrogen won't be so smug then, I can tell you!
  • from the no-shit dept.
    The speed of light is found to be "really fast"
  • from my knowledge, water created this way - ie condensation isn't yet ionised an doesn't have the ability to conduct electricity.

    if many of you know the celeron [tm somewhere], the ppga grid is visible from the top of the chip and I myself have had water covering every pin and moving it's way down the board just to test this very idea of water damage.
    [peltiers - not NO2] = P

    fyi no damage was incurred and I was damn suprised.
  • In all actuality, water is not an electrolyte. It's the minerals and elements in water which conducts electricity. This means that distilled water(condensation) does not conduct electricity, and therefore would not short out electrical equipment.

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