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Hardware

SubZero Chilled Alcohol PC Cooling 157

Posted by Hemos from the fun-with-substances dept.
Joseph Tan writes:"Tech-Junkie's own attempt on a liquid cooling project, this time we used a combination of liquid alcohol and frozen carbon dioxide. Less than -65 degrees Celsius was achieved, and amazingly our motherboard and CPU are still alive. "
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SubZero Chilled Alcohol PC Cooling

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  • CO2 is fine with ventilation. (Score:4)

    by Christopher Thomas ( 11717 ) on Sunday August 13, 2000 @09:40AM (#859232)
    What happens if somehow it malfunctions and you get deadly carbon dioxide released into your room.

    Carbon dioxide is not toxic.

    The only possible dangerous scenario would be filling the entire room with CO2, in which case you'd suffocate (no oxygen). However, with any ventilation at _all_ this can't happen.

    Caveat: Don't fill a basement with CO2. It's heavier than air, and will just sit there. If you start feeling drowsy after a minute or so, get out.

    Lastly, they had a total of 4 kg of CO2. Gaseous CO2 at room temperature has a density of about 1.7 kg per cubic metre. Even if *all* of the CO2 vapourized *and* they were in a basement and had no ventilation, the suffocating pool of CO2 would come up to about their ankles.

    In summary - No danger.
  • I wonder about the value of overclocking and pushing technology to the extremes in home computers, when the designers of supercomputers have realized that the performance gains achieved by pushing clock speed do not scale linearly with the cost. At some point a maximum speed will be reached and the cost of going any further will be staggering. The architects of high end systems have realized that massively paralell systems were the most practical way to obtain orders of magnatude increases in performance. I think that effort designing languages and programming pardigms to effectively use MPP architecture may be effort better spent than building fluorinert or alcholhol cooled overclocked systems. I suppose these systems are more akin to chopped channeled and supercharged 43 ford roadsters than to a 747 in terms of transporting people and cargo.

  • No, it wasn't. I was thinking of carbon monoxide. Funny thing is, look at all the redundant posts. At first, I just wished they'd all drop it. I even apologized a few times for my stupidity but now it's gotten to be just funny.

    For everyone reading this thread still (and I know you're out there, you keep replying): This was a mistake. I was thinking of carbon monoxide, not C02. It has been pointed out that I was wrong. Stop replying to me. It wasn't a troll, it was a brain fart. I know that C02 is relatively harmless, unless you touch it (dry ice will freeze the skin cells).

    kwsNI

  • Thanks. I knew that. Just a temporary brain fart (one of the possible, non-leathal side effects of too much CO2). Anyways, as you and every other /. reader except for John Carmack has pointed out, I've gotten my gasses mixed up and there is no real danger to CO2.

    kwsNI
  • Where do you get frozen Carbon Dioxide? And isn't that a little dangerous to handle?

    I like to buy it from Basket-Robbins ice cream parlors - they sell it by the pound. They stock up just before Halloween, since it's apparently quite popular for putting into punch bowls at Halloween parties.

    I like to buy a pound on the way back from lunch, crack it into small pieces with a rock, then drop the little chunks in my coworkers' coffee when they're not looking. I was surprised by how many people didn't realize what I had done to their coffee - I thought EVERY ex-high school/college student had played with dry ice at some point.

  • Excellent points, esp. (1). When I first read their method, I thought, "Air is a great insulator; that'll never work." I was quite surprised when they said the MB was cooled, but your suggestion the probe wasn't mounted correctly is probably correct.

    To reiterate - non-circulating air is one of the best thermal insulators. That's why home insulation is generally fluffy spun fibers. The material has many small pockets of trapped air, and the trapped air is the actual insulator.

    These guys did the same thing. They had a bubble of air around their CPU inside the bag, which probably significantly reduced any cooling to be gained from the dry ice & alcohol
  • They did -not- pump all of the air from the bag. They even added paper tissues, if you have noticed.The paper tissue alone would add one millimeter of air layer, if not more. And they had more than that around the CPU, if you have noticed. And the temperature measured was probably not on the CPU itself, but on the plastic bag's surface (from the inside). -65 would be WAY too good to be true if it was measured on the CPU, the thermal gradient is, unfortunately, much higher. Even the overclocking results show it clearly that the poor CPU was sweating bigtime. I stand by what I said. You are wrong.
  • Actually, that was accurate. Halon-style gases chemically interfere with fire. Enough oxygen remains in the room to be fairly safe, with Halon it may raise your heart rate -- other gases have other side effects. In large computer rooms, whether carbon dioxide or suppresive systems are used, it is common to have gas masks (filters) or breathing apparatus (air tanks) in the area. Lights, sirens, and delays to allow evacuation are standard -- but also common are some masks in case getting untangled from machinery takes too long, or in case rescue is needed. Particularly if the cause of the fire involved someone getting electrocuted, and rescuers have to linger in the area.
  • I believe many liquors have small amounts of methanol in them....this is what is "purified out" when you hear about purified spirits. The methanol actually often gives flavor, but will get you sicker faster in large quantities and contributes greatly to hangovers.

    Email me.
    Don't trust anyone over 90000.
  • It's not for the performance the oc'ers do it, it's the chanlenge of 'what if'

    In the case of one guy who was using liquid oxegen or nitrogen? and florinert and the transfer liquid. it would have been cheaper to BUY the board/memory etc for cost of doing the Overclocking. eg. $1000 for the florinert, $X for the LOX, $Y for the misc hardware and construction.
  • Actually, sportsmen and food workers who handle dry ice routinely know that the simplest way to handle it with a little newspaper. A few layers of newspaper provide enough insulation for easy handling. When using it to keep your fish frozen you can leave it inside the newspaper and the cold will leak out. And squeezing the newspaper will show you that is not a good idea.

  • CO2? (Score:1)

    by delmoi ( 26744 )
    Um, you know when you exhale? thats CO2 right there, the stuff is not at all dangerous. also, the Frozen stuff is not that hard to come by, and can be used in regular coolers for keeping food cold (the stuff dosn't melt, it turns directly into CO2 gas)

    I'm guessing this is a troll, but I thought I would respond anyway, you might have gotten C02 confused with CarbonMonoxide, which can cause problems.
  • When the fan broke down, the overclocker's mother said to him, "They have no more fans."
    "Dear woman, why do you involve me?" The overclocker replied. "My time has not yet come."
    His mother said to the servants, "Do whatever he tells you."
    etc. etc.
    ...the master of the banquet booted the computer that had been cooled with wine... ...and said, "Everyone burns out their Pentium IIIs first and then overclocks their Celerons, but you have saved the Athlon till now."

    (Okay, this one was kind of a stretch.)

  • Re:Electrolytic Caps Freeze (Score:1)

    by Anonymous Coward
    There are limits. Electrolytic capacitors become useless below some temperature. That temperature depends on the construction - which electrolyte.

    Electrolytic caps are formed from two pieces of foil separated by an electrolyte. A chemical reaction forms an insulating layer between the electrolyte and one of the foils. The high value of capacitance is due to the very thin separation of the electrolyte and one foil. The other foil simply provides contact with the electrolyte.

    Current flows through the ions in the electrolyte. That's where most of the ESR (equivalent series resistance) comes from. If the electrolyte freezes, there's not much movement of ions, and the ESR goes sky-high. Not much filtering going on then.

    If you cool your motherboard too much, the power planes are going to get noisy. Glitch city.
  • Thanks, someone already explained that to me. My mistake. Good thing I'm a geek and not a chemist...

    kwsNI
  • I think its on disc 2, Lain's uber-computer has a greenish-bubbly-liquid that she uses for coolant. Yet another example of anime showing future technology.. er.. okay, so at least 1 example ^^;

  • Boot linux dammit (Score:4)

    by CMiYC ( 6473 ) on Sunday August 13, 2000 @09:42AM (#859248) Homepage
    I really wish these massive overclockers would boot linux every once in a while. I say that because as they say in this one "At 616 it wouldn't boot Windows." Well...how far did it get? Maybe the IDE controller stops responding... if they'd boot linux then they'd at least have a better chance at seeing WHAT was failing...

    ---

  • Conclusion? (Score:3)

    by Accipiter ( 8228 ) on Sunday August 13, 2000 @09:44AM (#859249)
    All in all, it's been demonstrated that a system can actually run at sub zero temperatures.

    Um, if that was the whole point of this experiment....wasn't it a bit redundant? I mean, people have chilled their systems beyond this point, many with better results. What was the point?

    Anyway, the technique they used wasn't a very good one. The best way to cool a system is DIRECT CONTACT. They placed the motherboard in a bag, and submerged the bag in the chilled alcohol. No doubt, the cool air surrounding the bag lowered the temperature of the board (obvious by the overclocking results), but this is definitely inferior to less elaborate set-ups where cooling is *directly* applied to the system's components.

    The results of this experiment weren't all that impressive.

    This group was also risking the actual computer system BIG time. The fact they had to [try to] seal the board from the liquid makes this a risky undertaking. I'd feel more comfortable giving my board a bath in something a bit less conductive, like Mineral Oil.

    Plus, they like to destroy working laptops [tech-junkie.com]. Okay, I can see the 286's being whacked, but those 386's could be used for SOMETHING other than target practice, no?

    -- Give him Head? Be a Beacon?

  • AKA Dry Ice (Score:3)

    by brunes69 ( 86786 ) <`gro.daetsriek' `ta' `todhsals'> on Sunday August 13, 2000 @09:44AM (#859250)

    Obviously you didn't read the article at all, or this would be painfully obvious, even if you didn't know it beforehand. Frozen CO2 is dry ice, and is commonly available. It is not dangerous when handled properly, and has many common application, such as chemistry experiments, and making ice cream.


  • Where do you get frozen Carbon Dioxide? And isn't that a little dangerous to handle? What happens if somehow it malfunctions and you get deadly carbon dioxide released into your room.
    It is not that dangerous, considering that you exhale it every time... You should be more worried about touching it, since it could give you nasty frost bites. That is even more of a problem with the cooled ethanol, because of the better heat transfer (the sublimation of dry ice will actually prevent you from burning yourself upon short contact).

    Now 10 liter of flammable liquids and electronic components that can spark or overheat (duh). That doesn't sound like something you would like to explain to the fire department.

    Also the plastic bags is not a smart idea. Trapped air will reduce heat transfer, and a frozen bag gets brittle and breaks. Clearly the Fluorinert project was a lot better thought out (if only they had used dry ice instead of LN2).

  • another one... (Score:5)

    by chowda ( 161971 ) on Sunday August 13, 2000 @09:47AM (#859252) Homepage
    Here is what I expect to see next...

    Today Mr. Random Geek launched [slashdot.org] his motherboard and CPU into deep space hoping to achieve another 4 FP operations per hour. Mr. R.G. said "Liquid oxegen just wasn't cuting it anymore. I had To do something.. buying new hardware just isn't an option for me, I'll be overclocking this 486 for the REST of my life!"
  • I wonder what are the limiting factors to the range of temperatures that the components of a PC can support (both high and low). Since they are not subjected to mechanical stress, the metal parts should handle low temperatures well enough, and, IIRC, silicon is rather stable thermally.

    However, I am amazed that my own PIII is still alive at +75C, without overclocking. And let's not talk about the stability of Windows in such conditions. BTW, if anyone knows a solution which is less expensive than changing it (or than using dry ice ), I'd be glad to hear it.
  • You can try it with -your- system if you want, but, as I recall from high school chemistry, alcohol absorbs water from the air.

    Well, presumably you would use a closed-loop system otherwise the alcohol would evaporate.

  • no, the problem was the person who started the thread wasn't funny...

  • sorry (Score:2)

    by mattdm ( 1931 )
    Yes, you're right. I'm thinking even further back, of the 486DX/50 vs the 486DX2/66.

    --

  • Why not just use like a 70/30 mix of anti-freeze and water? That would probaly got to about -60 I think.
  • Picture this, was brought to you by my own twisted imagination:

    A typical full size tower running with this type of coolant circulating the entire computer in a clear plexiglass case, throw in a few of those those little plastic fish, some plastic flora, presto! An instant aquarium!

    The chicks will come running!

  • Why the hell is anyone trying to do the WHOLE mobo? The only thing that gets really hot is the CPU. And what do we have next to the CPU, neatly bolted to it, yup a big heatsink. Fill in the gaps round the edges and add a couple of tubes to a cold source (even an old freezer) and you've cooled the hottest part instantly without having to p**s about with bags etc... Some people obviously want to have a writeup that everyone's gonna criticise.
  • Seriously, people are waisting all their money to "deep freeze" their CPU's and Motherboards to achieve speeds they can achieve with just $10 CPU and Motherboard fans.

    I mean seriously, 500+MHz for a Celeron 333MHz is not a "GREAT" achievement. I have a Pentium II 300MHz that I have been overclocking to 450MHz for the last few years with just a regular CPU fan.

  • No, CO2 is hazardous on its own. If you don't know WTF you're talking about, then shut the Fortran up.

    Mammals breathe oxygen in and CO2 out. Most of our breathing processes are regulated by the amount of CO2 in the nearby atmosphere, and if you increase that even slightly, all sorts of bad shit start to happen.

    If CO2 is so nice to breathe, then there's a hundred dead Russian sailors who'd like to explain something to you.

  • If you just continue to inhale 100 percent of CO2, you die (we indeed can't take the oxygen out of CO2 and use that instead). But that's mostly due to lack of oxygen in pure molecular form, not due to the CO2 itself. It's similar to inhaling pure nitrogen: you'll die from that just as well, even though normal air contains 78 (IIRC) percent nitrogen that does you no harm whatsoever.

    As others have mentioned, excess C02 will result in symptoms of suffocation (even when enouugh oxygen is around), which means that you will be warned that something's up.

    --

  • he said he got 550 air cooled... so the experiment only gained them 16mhz and yes you are either drunk or severely handicapped
  • "Mmmmm, alchohol-chilled computer."
  • Where do you get frozen Carbon Dioxide? And isn't that a little dangerous to handle? What happens if somehow it malfunctions and you get deadly carbon dioxide released into your room. Really, I'd love to overclock a Celeron 300a to 1000 MHz, but I don't want to have to be in a Hazmat suite to do it...

    kwsNI
  • Sure; if you're afraid of a little instability, you shouldn't be overclocking anyway. :)

    --

  • I wonder if my sister's Arctic screensaver would finally work.
  • "A little for the computer, a little for me! A little for the computer, a little for me!"

    Ah, Simpsons.

    --Lenny
  • It's also used in CO2 fire extinguishers. My first use of it was as a long-term coolant for family camping trips (works wonderfully). We used it (among other things) to freeze ice packs that were used in the non-freezer cooler.

    The one way in which it might be dangerous would be if you had enough of it evaporate fast enough to displace a lot of oxygen in the room. In such a situation, it's actually much safer than Nitrogen because it's a build-up of CO2 which generates the asphyxiation response in the body (if CO2 builds up too much, you'll feel like you're suffocating -- even if you're getting enough oxygen!)
    With a Nitrogen overdose, on the other hand, you can suffocate without feeling weird because the Carbon Dioxide will be able to get out of your bloodstream even though there is no oxygen to take in.

    That having been said, I was in a basement room when a 200LB Carbon Dioxide cannister (used for POP) popped a valve. Even with such a rapid infusion of CO2 normal (commercial) ventilation appears to have been enough to prevent my suffocation. From that experience, I would expect that it would take some real work to evaporate enough CO2 to suffocate someone in a resonably ventilated space.

  • Re:Boot linux dammit (Score:3)

    by brunes69 ( 86786 ) <`gro.daetsriek' `ta' `todhsals'> on Sunday August 13, 2000 @09:54AM (#859270)

    The overclocking community and the Linux/*BSD community are totaly seperate types of Geeks. Because overclockers are usually totally into gaming, and most games are only available on Windows, they are usually quite Windows-centric, I find. Also, the most state-of-the-art gaming hardware is usually only available to Windows users. Most overclocking sites only make a big deal about Windows driver releases, Windows, games, etc.
  • Mommy, please make the troll go away. He scared me.

  • I did not know there was such a thing as solid alcohol.
  • I play paintball and there's LOTS of CO2 in the air and I've never heard of anyone having a problem (I guess if you inhaled the stuff strait you could suficate). Oh', and you can smell it. CO2 itself doesn't have a smell (I don't think)but the CO2 you buy will practically always be contaminated giving it a smell anywhere from cherry soda to motor oil. It isn't nice stuff to work with though (since it's so freaking cold.. though I guess why it worked in this case) so most people are switching over to plain ol' air or nitrogen.
  • Actually, the human body is sensitive to the concentration of CO2 in the air. When it goes up, the presence of CO2 in the blood triggers a suffocating feeling (e.g. hold your breath).

    However, inert gases (N,He...) do not trigger this feeling, but neither contribute to the oxygenation of your body. Since you are still breathing, you keep your blood's CO2 level low and feel fine. (Until you suffer from the lack of oxygen, which is what you are trying to avoid.)

    Conclusion: Get in a room full of CO2, you'll know quickly you should get out.
    Get in a room full of inert gases (or toxic ones), tougher luck.
  • 50 people post responses on an absurd statement about C02.

  • Some noted problems of the experiment... (Score:1)

    by Anonymous Coward
    1) Air/nitrogen gas are poor conductors of heat. They act as insulators. Any heat transfer/cooling that took place during the experiment was minimal.

    2) Freezing the plastic bag makes it brittle. It won't take much to crack the bag.

    3) Motherboards are not meant to be frozen. I've seen plenty of experiments that try to freeze the whole mobo. Taking a motherboard to -60 deg C will ruin a board over long periods of time.

    4) There are plenty of sharp objects on a motherboard to puncture a plastic bag.

    5) Any parts of the plastic bag not covered by the liquid could be melted by anything hot.

    They say that the thermometer's probe was placed next to the CPU on the motherboard. Was this on the inside or outside of the plastic bag? I have my doubts that the probe was correctly mounted.

    They say the processor before the experiment was flaky at 566Mhz but after the experiment was rock solid at 566Mhz. Due to the poor system of cooling, doubtful.

    Second, instead of just saying that we booted Windows and it didn't work, come up with a test suite that verifies different components on the mobo for functionality. For example, have tests that verify the pci bus, pci arbiter, keyboard/mouse controller, usb, ide controller, timers, ect... If you don't have these tests, Linux is a good place to start. View what comes up on the startup.

    As a suggestion, insteading of freezing the whole system, go after the heat producing areas such as the CPU. Come up with a simple system for liquid cooling just the CPU and you have a winner.

  • Methyl Alcohol? Isn't that methanol, which I believe even the gasses of which are poisonous? If so, they should've just got methylated spirits(regular alcohol with just enough methanol mixed in to make it poisonous to drink, i.e. untaxed).
  • That is 'Stolichnaya vodka' in case you don't know
  • Try chase your ice-cold Stoli with a beer. Watch the speed of CPU. / / / Incidently this reminds the a funny story. Many eons ago where 300bps links where the fastest once and only the managers were able to get those links from the company, my boss got the link and a dumb terminal, with a purpose to access mainframe-based operating system VM. VM terminal interface has never been designed for a slow links, so it worked like a shit. My boss finally discovered that drinking lots of beer slows him down so he's no longer typing that fast. Alas, he coudln't get the company to reimburse the cost of beer. Oh well ...
  • Frozen CO2 is nothing more than dry ice. When it sublimates it will turn into a gas (it is also found in the coke you are probably drinking while reading this), which is nothing more that what you breathe out every time. A whole block of dry ice can sublimate without it doing anything to you. What you may be thinking of is CO, or Carbon Monoxide, which *is* a deadly gas. But as for CO2 feel free to let it out... it's good for the plants.
  • Well, IIRC, the celeron series,and most of the modern pentiums have their Multiplier locked, so that you cant adjust that. Thats why it was a big deal that some of the Duron (i think) chips were shipped without the multiplier locked.

    So they can usually only adjust the voltage, and FSB.

    I didnt notice them mentioning the voltage at all in the article. Did i just miss it?

  • CO2 is toxic in concentrations of a few percent. Remember, not only do you have to get oxygen into your blood, you also have to get the CO2 out. You body cannot tolerate the blood concentration of CO2 that will result from a 10% atmospheric concentration.

    Ryan
  • Of course. My main point, though, is that (assuming it works) overclocking your motherboard by 5% will be far more significant then overclocking your CPU by 5% (or actually, by x%, where x is some number larger than 5 which I'm too tired to make up).

    --

  • > Carbon dioxide is not toxic unless you are exposed to insanely high levels.

    This isn't true. You just pulled that "fact" out of your ass. Concentrations of CO2 (that's dioxide, the stuff your exhale) around 10% will make you feel funny; 30% will quickly kill. CO2 concentration in the atmosphere is about 0.035% by volume. About 350 parts per million.

    Ryan
  • After about the third or fourth shot of anything good, you gotta start chewing your shots, or at least you think you do.
  • Your friendly neighborhood liquor or grocery store should have some.
  • You get solid CO2 by reducing the pressure of liquid CO2. IIRC, the phase diagram for CO2 shows that it takes a pressure of around 5 atm for liquid CO2 to exist. Phase transistion involves sublimation from gas to solid (or vice versa) at atmospheric pressure (no liquid phase possible).Basically, when you release liquid CO2 from a cylinder to atmospheric pressure it will turn into a gas or solid, depending on the temperature.As the phase transition to a gas requires energy (heat), you will end up with mainly CO2 solids.

    As for safety, your comment had me ROFLOL. Use either a well ventilated or a large room. You might recognize carbon dioxide's common name of "dry ice". Not that much of a hazard. They used 6kg of carbon dioxide in their cooling, which would occupy a total volume of approximately 3.4 cubic metres as a gas at STP (after it sublimes, which would take some time).Think of a box 1m high, 1m wide and 3.4m wide). Thus, a normal room (3m wide, 5m long and 2.5m high) with a volume of 37 cubic metres could in a worst case scenario end up with [CO2] of 10% or so. The only hazard would be if you had no air exhange, which is unlikely, as it could take hours to completely sublime.

  • a little blindness for me....

    --
  • HMMM, liquid oxygen. Also handy for overclocking your barbecue. [purdue.edu]
  • it'd be possibly dangerous to immerse the motherboard directly in the methanol due to localized heat spots that could cause boiling), and besides, the methanol would probably dissolve the plastic components.

    I thought you could only do about -20 with a methanol refrig. loop.

    --

  • Also, CO2 can disolve in alcohol. This provides a homogeneose cold liquid. I wouldn't go so far as to say that CO2 is not hazardous; solid CO2 has a temperature less than -78C, and can cause frost bite upon contact with skin. Also, CO2 is lighter than air, so sinks to the bottom of the floor (after it vaporizes), displacing the air that was down there. If the environment dies not have enough circulation, a person could pass out because of lack of oxygen, then end up on the floor where there is even less oxygen. BTW, water can be brought well below 25F by adding tabble salt (NH4NO3 works better). Also, antifreeze does not use normal alcohol, rather C2H4(OH)2, which has significantly different properties (let's not give anyone ideas about drinking antifreeze to get drunk).

  • I did not know there was such a thing as solid alcohol.
    Try -117.3 degrees celcius (-179 F).
  • You can _taste_ C02 (or at least I seem to be able to). That's what makes "bad air" so horrible, and club soda so nasty... :-)
    But I may be wrong, worse things have happened.
  • They did use methylated spirits, according to the article..
  • Modern Intel CPUs are all multipler locked. You cannot change the multiplier from what's burned into it at the factory.
  • It would have probably worked better if they used that fluorocarbon liquid stuff that somebody else used. Because it's nonconducting, you can immerse the components right into the liquid without having to worry about the insulating bag.
  • You clowns may be techy, but you obviously failed chemistry... Carbon MONoxide is poisonous. CarbonDIoxide is not even on the same planet as far as health risks go. Obviously you can't exchange either one for the 78% Nitrogen you need to breath, but CarbonMONoxide will kill your silly ass. I play paintball profesionally boys, and we fill the newbies all day long with that shit. Get a clue.... CO2 is fine for makeshift refrig...
  • That would be drowning, not poisoning. You would need to exclude all breathable oxygen from the air in the room. It's hard to do.

    It's true that sometimes people faint before they can get out of this sort of situation. It happens a lot with workers in steel tanks, where rust has removed all oxygen from the atmosphere.

    Bruce

  • Only if you use the methyl alcohol. And why is anyone using the methyl alcohol? To avoid having it taxed as liquor. So, blame your government for this sort of poisoning.

    Bruce

  • Are you sure that there isn't a chemical reaction involved with halon and fires? I thought it was a misconception that there would be no breathable air left in the room after a halon dump.

    Bruce

  • Re:C02 is not a good thing. (Score:4)

    by Windigo The Feral (N ( 6107 ) on Sunday August 13, 2000 @11:23AM (#859307)

    kwsNI dun said:

    Where do you get frozen Carbon Dioxide? And isn't that a little dangerous to handle?

    Actually, frozen Carbon Dioxide (as you so quaintly put it) is fairly readily available and mostly requires thick gloves to handle. It's otherwise known as "dry ice". ;)

    My father, who used to work for the water company here in town, could get it fairly easily; that plus water plus some flashing strobe lights added up to spooky cauldrons on Halloween for the kiddies. :)

    You can prolly get it at packing companies and the like. It's also what is commonly used to keep stuff like hearts for transplant (and biological samples) cold till they get where they need to be; the stuff is common enough that researchers in remote parts of Africa can get it to freeze samples of stuff like blood samples of Ebola patients.

    What happens if somehow it malfunctions and you get deadly carbon dioxide released into your room?

    Nothing, unless you've got a ton of carbon dioxide, in which case you MIGHT suffocate...but you'd have to have an awful lot of dry ice to ever get enough to suffocate yourself. (I think maybe you're confusing carbon dioxide (which is just good old dry ice, might give a freeze-burn but nothing serious) with carbon monoxide (which is a deadly killer since it replaces oxygen in your blood)...carbon dioxide is not poisonous, even the amount of dry ice to make a big cooler put out a lot of "smoke" isn't deadly (in fact, that's largely what they use for "smoke" effects in movies--dry ice in water! :) and your plants would love you (since they breathe carbon dioxide and exhale oxygen). :)

    Really, I'd love to overclock a Celeron 300a to 1000 MHz, but I don't want to have to be in a Hazmat suite to do it...

    No hazmat suit needed. Mostly some good, thick gloves if you're going to be handling amounts sufficient to cool a motherboard (seriously--that much is not enough to suffocate or cause any more harm than a nasty case of frostbite if you handle the stuff with bare hands). You may want to make sure you're in a well-ventilated room just to be safe, but that's pretty much true with any stuff that cold, not to mention computer equipment.

    (Chairman Kaga mode on) If memory serves me right (Chairman Kaga mode off) one of the competitors on "Iron Chefs" even used dry ice to freeze immature salmon to make sashimi. If the stuff is safe enough to pack hearts for transplant in and to freeze fish, it's safe enough to use on your computer. I've even used it before (along with glow-sticks in Ziploc baggies and a goodly amount of liquor and Mountain Dew :) to make a well drink called "swamp gas" in a cooler for Halloween parties (the carbon dioxide makes "smoke" effects from the water as well as bubbles--it's directly sublimating--and it freezes the alcohol into slush).

    Literally the only thing I've ever seen that classified dry ice as hazmat was in shipping papers for truckers, and they literally classify almost everything as hazmat (including paint, empty barrels, tires, etc.). :) Don't worry. Putting dry ice on your motherboard is not going to kill you unless you're in a very enclosed space (if that's the case, don't eat chili, as your own farts might well kill you in just such a case much as it did one infamous Darwin Award nominee :). You will probably see a lot of neat smoke-like stuff coming from the computer (no, it's not broken--that's just the dry ice sublimating and freezing the water particles in the air). Put plants nearby and they'll make lots of oxygen and probably grow really well. No harm done, save maybe to the motherboard and your budget. :)

  • well (Score:2)

    by mattdm ( 1931 )
    Well, correspondingly, when you increase the bus speed, you speed up the whole system (well, almost), whereas when you increase just the multiplier, you get quickly diminishing returns.

    I don't have any modern statistics on this at all (surely someone does) but I remember that the Pentium 50 systems that ran with the bus at 50 were slightly faster than the Pentium 66 systems with the bus at 33.

    --

  • Actually, as the carbon dioxide boils off from dry ice, it does give somewhat of a 'taste' to the air, slightly acidic. This is from the cold carbon dioxide dissolving in water, in the air or in your lungs, changing the PH.

  • Some anonymous coward dun said:

    Sure OK, you just get a big ol' bottle of CO2 and open the tap in a enclosed space. HAppy trails!

    Well, yes, if you're bloody stupid enough to go huffing it. For that matter, paint thinner and White-Out can also kill you by huffing them, and they take considerably less amounts to do so. For that matter, breathing water will kill you like that, because lungs aren't quite as efficient at gas exchange in water as gills are.

    You can't see it or smell it; but it keeps O2 from entering your bloodstream. Kinda like its friend Carbon Monoxide--you've heard of that one right?

    Warning: slight technical discussion ahead. Please skip if not interested in mechanics of suffocation. ;)

    Actually, carbon monoxide takes a hell of a lot less to kill you than carbon dioxide does, and it kills largely by a somewhat different mechanism. Specifically, carbon monoxide actually binds more tightly to hemoglobin than oxygen does, forming methemoglobin (which accounts for the bright cherry red skin that light-skinned folks who get carbon monoxide poisoning get). One can reverse this either by sticking the parties in a hyperbaric oxygen chamber (exactly as is used for people with the bends or nitrogen narcosis) to forcibly replace CO with oxygen, or (in the days before hyperbaric medicine was widely available) by giving one methylene blue (which also has the fun effect of turning one's urine blue).

    About the only one can suffocate from carbon dioxide is by being in such concentrations of it that it displaces oxygen to the point one would suffocate. It is pretty darn hard to do so; you either have to be practically huffing the stuff, in such deep depths that gas exchange of ANY sort is hard, or be on a planet such as Mars with almost no oxygen. (Dry ice is sufficiently safe that people have put hunks of it in coolers for food products, and even for organs meant for transplant. You have to have an awful lot of dry ice and a well-sealed room to successfully suffocate someone, and even then it isn't by displacing oxygen in the blood; rather, it's by displacing all other gases including oxygen in the air--in other words, instead of replacing oxygen in the blood, there's no oxygen to get to in the first place.)

    One of the rare cases of carbon dioxide suffocation that does occur--some cases of SIDS or "crib death"--occurs largely in infants under six months old who roll onto pillows or on their stomachs (and often have some miswiring or under-maturity in the "oxygen sensor" part of their brains that tell them to roll over or gasp for air); this is why nearly every baby-care group nowadays promotes "back to sleep"--putting babies on their backs to rest. SIDS generally does not occur in infants over six months of age (in those cases that do, it is either a case of something drastically wrong with baby's neural wiring or something wrong with the parents mentally [sometimes Munchausen's by proxy] where the parents actually have suffocated the kid).

    About the only way you'd die from carbon dioxide poisoning (in the amounts of dry ice it would take to cool a motherboard and processor--less than it takes to make "swamp gas" in a 55-gallon cooler) is by directly standing over the motherboard, having the computer sealed up and a tube leading out, and huffing the fumes from the tube. If you do that, you bloody well deserve a Darwin Award--please, get the hell out of the gene pool now, because you're making it skanky for the rest of us. :) With reasonable precautions (that do NOT include hazmat gear--mostly good ventilation such as computers should have anyways and heavy gloves if you don't want a nasty case of frostbite from handling dry ice) you should be OK. You've enough brains to know how to overclock the darn thing; surely we don't have to put "DO NOT EAT. CAUSES SEVERE FROSTBITE IF HANDLED WITH BARE HANDS. KEEP AWAY FROM CHILDREN." somebody-has-been-just-stupid-enough-to-have-done- this-and-sued-successfully warnings that most of the United States's population seems to require these days. :P

  • Why not just put a small chunk of dry ice directly on the heat sink of the CPU. I would not put it directly of the chip, but on the prongs of the heat sink.

    Sometimes the lessons of history are worth looking at.

    Remember the water-cooled mainframes? They had networks of heat pipes ducting heat from the chips to a heat-exchanger off the board. The heat-exchanger would transfer the heat to chilled water, which went to a rechiller of some kind. (Many buildings had cold-water systems for the air conditioning, so adding the computer into the building's chiller was a bang-easy deal.)

    (Speaking of weird systems, I had the honor of reviewing for Federal Computer Week a military PC, the Deuce by C3 Technologies, which was a computer designed to land on the beach with a platoon of Marines. It was water-proof, sand-proof, and damn near soldier-proof. By necessity, the system case was sealed tight -- no air exchange with the outside at all. Instead, you had an internal fan and a double-sided heat sink that ported heat to the outside of the case. The "portable" computer weighed 33 lbs, most of it in the metal of the case.)

    Take the idea of heat pipes to reduce "hot spots" and an active heat-exchange system -- and you can have a much-lowered thermal resistance for your system. Especially if you live where the air temperature gets over 110 degrees F.

  • Why? (Score:3)

    by Bruce Perens ( 3872 ) <bruce@perens.com> on Sunday August 13, 2000 @10:26AM (#859324) Homepage Journal
    Nobody has explained one thing, so far. Why bother to go to such great length just to overclock? People lap the top of their CPUs for better contact with the heatsinks. OK, that will run continuously. They drop their motherboards in cooling fluids. What do they do with the computers afterward? Develop a habit and become regular customers of Airco? Some say that these are video gamers, but I doubt that gamers really need the speed quite this badly. The systems aren't going to stay cool for that long.

    All that I can think is that this is the computer equivalent of drag-racing, and can't really serve any practical purpose.

    Bruce

  • I think you can drown on a gas. Choking involves obstruction of the airway.

    Bruce

  • Everything was pre assembled and tested to make sure that it actually ran before hand.
    These guys show they know hardware.
    A fresh format and installation of Windows 98SE meant that on the software side everything was pristinely clean.
    But they sure don't know software!

    ;^)

    Now hiring experienced client- & server-side developers

  • From http://www.h3r.com/halon_wk.htm [h3r.com]:

    What Are Halons And How Do They Work? They are low-toxicity, chemically stable compounds that have been used for fire and explosion protection throughout this century. Today, Halon 1211 (a liquid streaming agent) is used mainly in hand-held fire extinguishers and Halon 1301 (a gaseous agent) is used mainly in total flooding systems. These halons have proven to be extremely effective fire suppressants, which are clean (leave no residue) and remarkably safe for human exposure.

    Three things must come together at the same time to start a fire. The first ingredient is fuel (anything that can burn), the second is oxygen (normal breathing air is ample) and the last is an ignition source (high heat can cause a fire even without a spark or open flame). Traditionally, to stop a fire you need to remove one side of the triangle - the ignition, the fuel or the oxygen. Halon adds a fourth dimension to fire fighting - breaking the chain reaction. It stops the fuel, the ignition and the oxygen from dancing together by chemically reacting with them. Many people believe that halon displaces the air out of the area it is dispensed in. Wrong! Even for the toughest hazards, less than an 8% concentration by volume is required. There is still plenty of air to use in the evacuation process.

    I consider myself newly educated. :)

  • HAHAHAHAHA! (Score:4)

    by Signal 11 ( 7608 ) on Sunday August 13, 2000 @12:31PM (#859333)
    What they don't realize is that alcohol is a dielectric - they could *soak* their mobo in the stuff without problems and get substantially better cooling too!
  • Alcohol is a really flammable liquid. I'm wondering whether it isn't rather dangerous to use it for cooling?

    Imagine when circulation of the liquid stops and it starts to boil or something. Then, with many electric equipment around it, it looks to me like you're really *asking* for nasty accidents (computer on fire etc.)
  • I've got a bottle of Stoli in the freezer now. Maybe I'll give it a try. Or maybe I'll just chill -- I've noticed that after a shot or two, having a slower CPU doesn't bother me as much.
  • Or, you could start windows in bootlogged mode. A somewhat less dramatic solution than installing linux for this purpose.

    Thats hold down ctrl for windows 98, press f8 for windows95. Look for bootlog.txt.

  • There is such a thing as too much cool (Score:5)

    by satch89450 ( 186046 ) on Sunday August 13, 2000 @10:38AM (#859349) Homepage

    I've read the various stories about cooling computer components/motherboards down using insane ambient temperatures. Many of these guys forget a basic tenant of computer design: the temperature of the silicon die in each package is what is important.

    The ambient-temperature specification quoted in the spec sheets take into account the thermal resistance of the packaging in order to keep the die within an acceptable range of temperature. If you keep the ambient temperature at the package at, say, 0 C, and the thermal resistance between the packaging and the cooling method is insanely low, then all components will run within specification and you can overclock until you run into race conditions in the processor itself, or perhaps in support circuitry.

    On selected hot-running components like the processor, you might want to drop the ambient temperature a little bit more -- say to -20 C -- to compensate for the compromises that CPU makers make between thermal resistance of their packages and other considerations. The goal here is to run the hot die, not package, at the lower end of its temperature specification.

    This does NOT mean that you should subject cool-running components to the same out-of-range ambient temperature, as the cooler-running dies will then be running outside of thermal specification envelope.

    In this particular experiment, they cooled EVERYTHING on the motherboard, plus a video card and network card. In their writeup they say that they picked a cool-running card, as opposed to a heat-filled monster. The experimenters subjected all the components, perhaps ineptly, to the same ambient temp of -60 C. Even military components are designed to run above -55 C. Most commercial-grade components are speced to run at an ambient of 0 C.

    The result could be predicted: The overclocking of the cool-running Celeron chip was sabotaged by the overcooling of the support chips.

    Just my pair-o-pennies(tm).

  • You're right, it's not choking. How about suffocating? I believe that works.

    kwsNI

  • It's pretty clearly become a hobby. Some people get started in overclocking because they see it as a way of getting a given performance for cheaper. After a while, the idea of getting cheap performance sort of falls by the wayside, and the idea is to see how much performance you can get out of a given system, whether it's cheaper to get it that way or not. It's fun playing with cool equipment, trying to get the absolute maximum out of a computer, and having bragging rights about how fast you can get your processor to go. It makes about as much sense as programming yet another Napster client clone; people do it as much to have fun doing it as because they actually expect the product to be particularly useful compared to the stuff that's already out there.

  • I'd get top of the line chips and clock them faster than any such chip you could buy. That'd be the only reason for me. I'd also never trust an overclocked system, but that's just me.
  • Linux would be a nice change. I'm sure it would have less problems than Windows. However, I also wish they'd skip increasing the FSB speed, and work on the multiplier.

    It's a well known fact of overclocking that increasing the FSB is a much less reliable method than increasing the multiplier. Why? Well, when you increase the FSB, you're driving all the devices in the system faster, and at non-standard clock rates as well. You stand a good chance of having the IDE or video controller stop the system. When you increase the multiplier, you're only touching the CPU.

    He might have been able to get that Celeron up to 650 or possibly higher if he left the FSB alone and cranked the multiplier.

    -Todd (running a Celeron 300a at 566 with a combination of multiplier and FSB increases, and air cooling only)

    ---
  • Funny that they didn't realize that putting the mobo in a plastic bag creates a thermal shield (air) around it! And air is the BEST thermal insulator, after vacuum. These guys must be pretty weak in physics, I figure.

    Actually, putting the mobo in that bag should have increased the temperature around the CPU: I guess the fan was not deactivated, so it was turning inside a very limited space, which creates a considerable mechanical resistance to the circulation of the air. This, in turn, makes the fan itself overheat, and hence the CPU, too.

    Really, really dumb....



  • Providing this is an intel-based chipset (as opposed to the cooler-running PPC G3/G4 architecture), computer hardware could also provide the following funtionality:


    grilling on the heatsink

    hair drying (hook a hose up to the exhaust fan)

    space heating in the winter (exhaust fan again)

    and to beat a dead horse- cup holder (cd rom tray)



    Seth
  • No hazmat suit needed

    Christ, I wear a hazmat suit just to run Windows!

  • Where do you get frozen Carbon Dioxide? And isn't that a little dangerous to handle? What happens if somehow it malfunctions and you get deadly carbon dioxide released into your room.

    Carbon dioxide is not toxic unless you are exposed to insanely high levels; it's one of the most common gasses in our atmosphere. You're probably thinking of carbon monoxide, which is toxic. One of the most popular uses for carbon monoxide is for suicide-by-car-exhaust.


    My mom is not a Karma whore!

  • You can try it with -your- system if you want, but, as I recall from high school chemistry, alcohol absorbs water from the air. The -alcohol- is okay, but the real-world liquid isn't pure alcohol, it's alcohol/water mix.

    (In other words, it's like water being 'theoretically' non conductive - it's okay on paper, but in practice you can't get pure alcohol, or pure water, right up against the motherboard.)

    Also witness that dampening the bottom of the motherboard with the alcohol, as described in the article, did, in fact, short it out.

    --Parity

  • Re:I'll show you cold! (Score:4)

    by Frymaster ( 171343 ) on Sunday August 13, 2000 @01:29PM (#859376) Homepage Journal
    Just bring up here to Saskatchewan (Canada)

    I can just see the beer ad now...

    "Hi, my name is joe and I have dual-proc 200MHz Bombardier sunk under the ice at the North Battleford Bonspieler and Overclockers Community Association and it's doing 3.2 Tflops. That's almost 5 Tflops in Metric (7.2 American, 8.30 in Newfoundland). thank you"

  • Try starting a fire in midwinter sometime... ;)

    To reach the flashpoint of alcohol, whatever it is, you'd have to heat the alcohol by about 120degrees-F more than usual (assuming alcohol is
    normally at around 50-70dF, this stuff was at minus 65dF, at -least- (that was the inside-the-bag atmosphere temp wasn't it?); making it, then, much harder to catch on fire.

    Of course, if it -did- catch on fire, it'd be just as dangerous as any other alcohol fire, so, well, it wasn't exactly 'safe as houses' as it were.


    --Parity
  • That's not what they told us.
    I'll look up my course notes.
    I did question them, but they were adamant about it being toxic. They couldn't tell me why though.

    I've done a web search, and most of the information I've found just mentions toxicity due to displacement of oxygen from the atmosphere, as per my original post. The limits that are specified are either very high when reporting actual test results (in the 50% v/v range to kill rats), or are in the low-percentile range and explicitly stated to just be the highest limit allowed by the classification schemes used.

    One reference mentioned acidification of the blood as an effect of high CO2 concentration, but only to mention that it wasn't significant in the few-percent range. It would probably be relevant at high pressure (e.g. for divers), but I'm not sure if it's a concern at STP.

    Hmm.

    Solubility of CO2 in water, according to Ye Rubber Bible, is just under 0.1 g/L, for about 0.002 moles/L. Water has a "concentration" of about 56 moles/L. This gives a relative concentration in water of about 3.6e-5 M/M, for a pH of 4.4 assuming 100% dissociation.

    What is the minimum safe pH of blood?
  • Caveat: A pH of 4.4 is a worst-case estimate, as other dissolved substances in the bloodstream will make the CO2 less soluble (witness the effect of dropping salt into a can of Coke).

  • Um, C O2 (not C02 as you typed) is produced in normal mammalian cellular perfusion, and freed to the atmosphere every time you exhale. It takes a HUGE volume of carbon dioxide in an enclosed room, before it becomes a problem for further respiration. Your potted plants will thrive, as they take in carbon dioxide, and produce the free oxygen you need.

    Frozen C O2 is called "dry ice," and is used to keep meats and dairy products cold in shipping. In normal room temperatures, it won't melt, but it will sublimate directly to the gaseous form, which, as stated above, is perfectly normal around we mammals. If you want some frozen carbon dioxide, go to an ice cream store and ask for a bag of it.

    Dry ice, aka frozen carbon dioxide, is dangerous to handle. You need tongs or thick gloves. If you touch it directly, it'll freeze the cells of your skin and muscle tissue quickly, creating a burning sensation then killing the flesh. If you don't touch it with your skin, though, it's pretty forgiving.

    This isn't like dealing with halon, or carbon monoxide. Halon is released as a fire retardant, and works by denying oxygen that fuels a fire. Carbon monoxide is a byproduct of petroleum burning, and reacts toxically with living cellular tissues. These are highly dangerous materials.

    In short, carbon dioxide in its frozen form is slightly more dangerous than liquid nitrogen, is not as cold as liquid nitrogen, and has about the same health risks involved in breathing and direct contact.

  • Thank you, mister grade 3 science teacher.
  • I think we're about to see the ultimate integrated system. First, your home computer combined with your stereo, then your DVD player, letting you make an out-of-this-world enterntainment system. Now... It's your fridge! Yes, now, your refridgerator can now be integrated in with the computer, stereo, and DVD player, giving you the ultimate entertainment system that keeps your beer cold. :o)

  • Frozen CO2, also known as dry ice, is available from a lot of places. You used to be able to get it from just about anywhere that did a lot of food freezing, though they're a bit more stringent about selling it these days. It's not terribly dangerous, either; you're putting out CO2 all the time. You just need to have decent ventilation in the room. We use dry ice/alcohol mixtures in the lab all the time, and everyone agrees that it's more of a hazard as a freezing risk than from a poison standpoint.

    It's also important to point out that CO2 is a powerful stimulant, so if it starts building up you'll get very twitchy and often start to panic. This will generally cause you to run out of the room, which is exactly what you need to do to save yourself. This is not an accident but an evolved survival behavior. Your body is also quite good at getting rid of CO2, so once you reach clean air you'll recover quite quickly.

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