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Pushing a CPU to Heat Death, Intentionally

Posted by timothy on Thu May 22, 2008 09:28 AM
from the or-maybe-it-will-loaf-along dept.
Hardware Hacking Hardware IT
sdougal writes "This site is showing a Pico-ITX board running Ubuntu with no cooling whatsoever. They even let the public guess how long it would last: 'Last week thousands of you placed bets on how long the new Pico-ITX board from VIA, the VIA EPIA PX5000EG, can last without any cooling whatsoever. An ARTiGO Builder Kit was offered as the grand prize. Yesterday afternoon the voting stopped and the Naked Pico Challenge started in earnest. We simply loaded up Ubuntu 8.04, set it to work playing an mpeg-4 video and then removed the heatsink, leaving the CPU and VX700 chipset bare to the world. We recorded the event here in this video and set up a live video stream so you punters can keep a watchful eye on the PX5000EG as it works away.'"
+ -
story

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Submission: How Many CPUs Can Work With No Cooling At All? by sdougal (1154205)
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  • Ehh, it's been done before (Score:5, Interesting)

    by elrous0 (869638) * on Thursday May 22 2008, @09:29AM (#23504988)
    Anyone remember Patrick Norton frying that CPU on "The Screen Savers [wikipedia.org]" back in the TechTV days? Patrick and Leo were building their annual "Ultimate Gaming Machine" (using all the best components available at the time) and his Nortoness forgets to put the heatsink on the CPU. They turn it on, and within minutes, they smell something burning. They had just fried one of the most expensive CPU's you could buy at the time, right there in front of God and the nation.

    It was an expensive lesson in the importance of the heatsink.

    Of course, many of us can remember back when CPU's didn't even need heatsinks. My first build was a 486SX with a zif chip slot and no CPU cooling--hard to believe now.

    • Re:Ehh, it's been done before (Score:5, Interesting)

      by TheGratefulNet (143330) on Thursday May 22 2008, @09:39AM (#23505190)
      I was at one of the audience tapings for 'TSS' in san francisco, a few years ago. very sad to see the show leave, taking all that good geek (true geek) talent with it.

      I once sent an amd k8 system to a friend in the mail. I made the mistake of leaving the big heatsink (I think it was a barton chip and those were VERY hot back in the day) attached. the pc was sent ground, I think, and so it didn't get the best treatment. turns out that the heatsink came off the cpu socket and was doing some kind of 'round the world tour' inside the pc case! when he opened it up, there were ding marks from the sharp edges of the heatsink all over the mobo ;(

      that was bad. but it gets worse. my 'genius friend' decided to just try it as it was and not even bother to fix the heatsink back to the chip!

      I think in 5-10 secs, he -guaranteed- that that system will never run again. I would have liked to know if the mobo was still working - but now, the whole thing is toast.

      he didn't know? really? a BIG HUGE HONKING heatsink and he thinks he can turn on a system without it?

      sheesh.

      now, that was years ago. today with the core2 arch, you almost don't NEED a heatsink. its amazing. I have overclocked core2 chips (see 'BSEL mod' for changing 800fsb to 1066fsb via some conductive paint) and STILL the chip is cold to the touch when I run memtest86. my bsel mod photos are here, btw: http://www.flickr.com/search/?q=bsel&w=47907743%40N00 [flickr.com]

      its now my usual procedure to install a fan speed control and set it to MIN for all my core2 systems that I build. I love the fact that even at slowest rpm, it still never gets hot enough to even pull your hand away from the hs/fan. amazing..

      I also do have a via epia that I use for my mythtv box:

      http://farm3.static.flickr.com/2010/1890660635_273662e3c9_o.jpg [flickr.com]
      http://farm3.static.flickr.com/2299/2005750966_a1b8d242b3_o.jpg [flickr.com]

      in that 2nd photo, you can see its drawing 24watts (with a kill-a-watt lcd meter). its 100% fanless, uses a 1ghz cpu but it DOES get quite hot to the touch so I leave the top case skin off; that way I can get by with no fan at all. its been doing my myth-tv recording (using hdhomerun HD tuner box, networked) for about half a year now; no reboots and very reliable.

      low power systems are cool ;)
      • I've had two CPUs die from heat death when their cooling fans became clogged with dust, cat hair and pot smoke. The latest box's motherboard has a thermometer hooked up so if it reaches a certain temperature the power will shut off.

        It's gotten flakey lately when booting to Windows (although it boots to Linux flawlessly. I'm not sure if this is a good or bad thing to say about the respective OSes). The default is Windows, and it would reboot continually until Windows finally "caught" (unless I told LILO to g

        • Re:Ehh, it's been done before (Score:5, Funny)

          by frosty_tsm (933163) on Thursday May 22 2008, @10:56AM (#23506480)

          I've had two CPUs die from heat death when their cooling fans became clogged with dust, cat hair and pot smoke.
          I'm not sure if this story should result in a LOL-cat or a computer-shaped bong...

        • Re:Ehh, it's been done before (Score:4, Interesting)

          by Feanturi (99866) on Thursday May 22 2008, @11:20AM (#23506854)
          I've seen a few power supply deaths, in which case two of the systems had been working fine right up until the last time they were turned off. One of them had a bad switch (old AT) which made it difficult to turn the system on, so the user had stopped turning it off altogether, for about a year. Then I needed to install a network card in their system so of course had to turn it off. It never powered up again after that, once the system had cooled, rewiring the switch didn't change anything, and the PSU needed to be replaced. Temperature change killed it.

          Another one was one of my own, that was near a window, and that side of the room got very cold in the winter. My systems always run 24/7 because this way the internal temperature stays somewhat consistant, avoiding chip creep and spreading solder joints. But then one day, when it was particularly cold out and so also very cold in that corner, I wanted to move another hard drive into it. At first it powered back up for about 30 seconds then shut down. Tried starting it several times but each time the running interval got shorter, until finally, it just wouldn't turn on at all. Replaced PSU and all was fine. Temperature change killed it.

          A third one, this time the one in my gaming rig, developed its problem while in use. I was playing Oblivion or something intensive like that, and it was summer, very hot outside and in - my apartment is very poorly insulated as you may have guessed by now. The system started shutting down about every half hour, so after a couple instances of that I stopped playing, but later in the evening when things had cooled down, it was still doing it. Replaced the PSU and it ran fine after that. Temperature killed it.

          Quite a few hardware failures I've encountered, CPUs, hard drives, video cards, whether my own or friends or work-related, I've been able to blame on temperature one way or another.

        • Re:Ehh, it's been done before (Score:4, Interesting)

          by Lord Apathy (584315) on Thursday May 22 2008, @02:23PM (#23509782)

          Have any of you lost the power supply in a PC?

          One morning I woke up and noticed my computer was off. I never turn my computer off. So I did what came natural, I turned the fucker back on. The powersupply blew the fuck up! I mean Boom! There was smoke billowing out the side and flame shooting out the fan port. The fucking fan in the power suppy was on fire! It was cool as fucking hell!

          Fried everything in the damn computer but the CPU, memory, and graphics card. Harddrives, cdroms, tapedrive, ethernet/sound card, MB.. Gone. The only thing I can think of is it fried everything on the +5/+12V connection and since the surviving parts where 3V they lived. That is the best I can come up with.

          • Re: (Score:3, Informative)

            by master_kaos (1027308)

            I bought a $20 test device to confirm the deadness of PSUs.
            Wow, why? I use a (basically) free paper clip. Connect one end of the paper clip to the green wire, and the other end to any black wire (ground) and press the power button... if it doesnt power up, means it is dead, if it does power up it is most likely fine

            • Re:Ehh, it's been done before (Score:5, Funny)

              by baggins2001 (697667) on Thursday May 22 2008, @02:15PM (#23509678)
              I usually just put my tongue across the 26 connectors and turn the power on. If my penis doesn't tingle then the power supply is bad.

                • Re:Ehh, it's been done before (Score:4, Interesting)

                  by beav007 (746004) on Thursday May 22 2008, @08:02PM (#23513272) Journal

                  Your ideas intrigue me, and I would like to subscribe to your newsletter.
                  There, fixed that for you.

                  My 3 favorite tools are made from paperclips.

                  The power supply tester
                  Creation: Unbend a paperclip, and then bend it into a big U shape.

                  Usage: When you are unsure whether a PSU works (a) disconnect it from anything it is connected to (b) insert one leg of the U into the hole in the 20/24 pin motherboard power plug for the green wire (c) insert the other leg into a hole for a black wire (d) plug the PSU into power and turn it on.
                  If the fans spin up, then the PSU at least partially works. At this point you can use a multimeter to verify the voltages of the different rails with no load.

                  The CD ejector
                  Creation: Straighten a thick-gauge (strong) paperclip, and then put a loop in one end that is big enough to put your index finger through, at least to the first knuckle (this helps with gripping it during use).

                  Usage: When you need to eject a CD from a powered-down computer (laptop OR desktop), push the paperclip into the emergency eject hole. On a laptop, this requires very little force, but on a standard (5.25") Desktop CD-ROM drive, this will take quite a bit of effort.

                  The multipurpose grabber
                  Creation: Straighten a regular paperclip, and put a loop on the end, as you did for the CD Ejector. On the other end, put a 90 degree bend, 2mm from the tip.

                  Usage: You can use this tool to remove or move jumpers (very handy for IDE hard drives), and to remove stuck floppy disks from floppy drives (use the R/W hole or 1.44MB hole as an anchor point).


                  Hope that was helpful to you.



                  Note: why use "creation" in the instructions? Well, I've had all the necessary components sitting in my drawer for years, and they stubbornly refuse to evolve into anything useful...

      • I ordered a Tunderbird 900mhz when they were "the big thing." The guy who was building it fried 6 CPUs and 4 motherboards before he figured out that it wasn't a good idea to bench-test them without a cpu fan. Helps to read the instructions ...

        Another guy (who builds systems "on the side") asked me about one that he similarly toasted - it would boot, but wouldn't run Windows. I told him that he now had a very expensive dos-box, and to enjoy running the original Doom at 1.2 ghz.

        • I ordered a Tunderbird 900mhz when they were "the big thing." The guy who was building it fried 6 CPUs and 4 motherboards before he figured out that it wasn't a good idea to bench-test them without a cpu fan.

          I built myself a 500MHz Athlon system back when they first came out, and a few years later I happened to have the case open and noticed that I had never plugged the fan in!

  • The rule of thumb is.... (Score:5, Interesting)

    by Ancient_Hacker (751168) on Thursday May 22 2008, @09:32AM (#23505044)
    The rule of thumb among engineers is: One square inch of flat aluminum surface will dissipate one watt at room temperature and rise about 20 degrees Farenheit.

    A CPU chip with 900+ pins run a bit cooler as it's a it more than one square inch if you an include the substrate, and a certain percentage of the heat will conduct itself down the pins.

    • I predict a lot shorter now that the page with the video is linked on the Slashdot front page.! ;)

    • You don't need to know how thick it is? 'cause I guarantee this won't work with aluminum foil for example.

      • Re:The rule of thumb is.... (Score:5, Informative)

        by Anonymous Coward on Thursday May 22 2008, @11:42AM (#23507182)
        the formula for convective heat transfer (transfering heat from the surface of the heatsink to the air) doesn't involve thickness. A very thinly-sliced 12"x12" sheet of aluminum, uniformly heated to 200F, will transfer just about as much heat/second to the air as a thick plate of 12"x12"aluminum @200F will (there will be some differences, because the plate has a *bit* more surface area, but I digress...)

        However, CONDUCTIVE heat transfer (getting the heat to go from the "hot" end of the heat sink to the tip of the fin) is directly proportional to surface area. This means that, were you to use a single sheet of aluminum foil as a "fin" on your heatsink, you would not be able to get the heat to actually travel effectively to the tip of the fin where it could be removed via convection. Thus you'd wind up with a very hot "hot" end of the heatsink (near the chip, which does you no good), and a cool "cold" end of the fin (which is worthless, as convective heat transfer is proportional to the difference between the surface temp and the air temp). If you were to instead use a thick sheet of aluminum as your "fin", that would allow the heat to easily travel from the "hot" end to the tip of the fin, where the air could take it away.

        However, you can get the best of both worlds by using multiple thinly-sliced sheets of aluminum. Same cross-sectional area as the thick slice (for good conduction), and maximum surface area (for convection). Which is exactly what most heatsinks look like.

  • The video (Score:5, Funny)

    by nawcom (941663) on Thursday May 22 2008, @09:35AM (#23505094) Homepage
    They should make the mp4 hours of video of hardcore pornography, and we can all make bets on what the final frame that it shows before locking up and shutting down will be about. Blowjobs, anal, AtM, Bukkake, fem domination, tentacle sex, etc. It will bring more people to RTFA and WTFS (Watch The Fucking Stream).

  • Must...resist...saying (Score:5, Insightful)

    by Rosco P. Coltrane (209368) on Thursday May 22 2008, @09:36AM (#23505120)
    slashvertisement. There I said it.

    VIA showing off their board, offering a VIA-equipped toy to someone, disguising the entire thing as a geek event and plastering it on geeky sites. Gee, that sure is great news for nerds, stuff that (doesn't) matter...

  • Ummm, copying VW folks? (Score:4, Interesting)

    by R2.0 (532027) on Thursday May 22 2008, @09:36AM (#23505122)
    They've been doing this with aircooled VW engines for probably 50 years at shows and races. Pull the fan belt, drain the oil, and put a brick on the accelerator. Everyone pays a buck to bet on the time, and with any luck the engine explodes spectacularly, much to the crowd's pleasure.

    Yet again, "on the internet" somehow makes it original...

    • Re:Ummm, copying VW folks? (Score:5, Insightful)

      by Anonymous Coward on Thursday May 22 2008, @09:43AM (#23505244)
      Yes, well... everyone everywhere should stop doing interesting things, because someone, somewhere may have done something similar. You don't per chance work for the US Patent Office do you? Software Patent Division?

    • Re: (Score:3, Insightful)

      by geekoid (135745)
      Who said it was original?

  • Why should it even crash.. (Score:5, Insightful)

    by SD-Arcadia (1146999) on Thursday May 22 2008, @09:39AM (#23505180)
    If a CPU is going to crash or go up in smoke after heatsink removal under load it will do so within 30 seconds. Since it hasn't done so yet and considering it's a 1W energy efficient CPU the only effect should be a reduction in its longterm lifespan (maybe it will only run 2 years rather than 8). I don't see the excitement here, until they take a hairdryer to it which they say they will do after two weeks. That should be interesting.

    • Re:Why should it even crash.. (Score:5, Informative)

      by blind biker (1066130) on Thursday May 22 2008, @09:57AM (#23505466) Journal
      Not true at all. Have you heard of electromigration? Its rate increases with temperature, exponentially (actually, by the Arrhenius law). Accelerated electromigration failure tests are and have been extremely common both in the industry as in research institutions.

  • AMDs don't need CPU fans, either (Score:5, Interesting)

    by Anna Merikin (529843) on Thursday May 22 2008, @09:44AM (#23505258) Journal

    Like the ole Timex watch that "took a licking and kept on ticking" my desktop box, an ancient AMD Sempron 2600+ with a VIA chipset, unknown to me, lost its power connector to the CPU fan, which I only discovered by accident when replacing a hard disk drive. The CPU was hot enough to scald my finger, but neither its performance nor its stability has suffered one bit.

    Of course, the heatsink was still connected. But the Sempron was IIRC most definitely NOT a low-power cpu.

    Yes, I reconnected the CPU fan. But at least I know my sh*t can take the heat.

    No video is available ;o{ .

    • Re:AMDs don't need CPU fans, either (Score:5, Informative)

      by AdamWill (604569) on Thursday May 22 2008, @10:15AM (#23505726)
      That's because of a rather famous incident with the *previous* generation of AMD chips.

      Intel had recently introduced an overheat sensor into their CPUs. They still have them, I think. There's basically a thermal probe included in the CPU packaging, and if the temperature goes over a certain critical level, the CPU starts throttling itself down, until the temperature goes down to a safer level.

      Tom's Hardware (probably being paid by Intel...) did a video experiment on this. They got an Intel (early P4, IIRC) and a then-current-gen Athlon, started them both playing Quake 3, then removed the HSF.

      The Intel chip promptly throttled itself down to 400MHz or so, and kept running the game (rather slowly). The Athlon crashed, hit something like 200-300 degrees C, and burned a little hole in the motherboard.

      After that little stunt, AMD started building overheat sensors into their CPUs quite fast.

      I saw this in action on one of my own machines, a Shuttle SN62K, a couple of years back. That machine has a known issue with the motherboard fan headers dying after about a year of use. It's also a very quiet system. I was using a 2.4GHz Celeron in it at the time. The fan header died and the fan (only fan in the machine, if you know Shuttles) stopped working. The CPU throttled itself down to 800MHz and kept right on going, for two weeks, before I actually noticed.

  • I really doubt (Score:5, Insightful)

    by LM741N (258038) on Thursday May 22 2008, @09:46AM (#23505300)
    that this is an experiment. They already know that the device will run indefinitely. No company would do a media event like this that would shed bad publicity on their product- except Microsoft, LOL.

    • Re: (Score:3, Insightful)

      by sm62704 (957197)
      No company would do a media event like this that would shed bad publicity on their product- except Microsoft, LOL.

      How about Sony and their rootkit? What about SCO and their Linux licenses? What about the RIAA and their lawsuits against computer-illiterate grandmothers, twelve year olds, and dead people?

      What about Fox and American Idol?

  • "Heat Death" (Score:5, Interesting)

    by ObjetDart (700355) on Thursday May 22 2008, @09:48AM (#23505312)
    Sorry to nitpick, but doesn't the term "heat death" usually mean death by maximum entropy (i.e. no heat), and not death by heat?

  • Done, accidently, before (Score:4, Interesting)

    by Toreo asesino (951231) on Thursday May 22 2008, @09:49AM (#23505328) Journal
    We had a headless linux server that one day started beeping constantly for no apparent reason. With every intention on fixing it, after a couple of weeks of it still running ok, we just assumed the speaker had died so just ignored it (the server room being sealed away as it was). Then one day we had to move the servers to another room, went to pick the machine up, and "Jesus! This thing is boiling!".

    It was some ancient AMD chip that we literally couldn't buy new fans for any more, so we just snipped the speaker cable and let it carry on.

    Naturally, the Linux guys claimed if it had been Windows, we'd be looking at a dead server at this point in time :)

      • Re:Done, accidently, before (Score:4, Informative)

        by Megane (129182) on Thursday May 22 2008, @12:58PM (#23508484)
        That wooshing sound is the point going over your head. It would have been a dead server with Windows because Linux has much better thermal performance, due to the way it idles with the halt instruction. Or at least that's the common wisdom and what GP was referring to.

  • FUD Ammo... (Score:5, Funny)

    by PinkyDead (862370) on Thursday May 22 2008, @09:50AM (#23505352) Journal
    How long before we see this up on www.microsoft.com/getthefacts/ with the headline:

    "Linux will set your computer on fire."

    You have been warned.

  • I don't get what the big deal is... (Score:4, Funny)

    by ramon_omar (1292652) on Thursday May 22 2008, @09:52AM (#23505396)
    I mean, I can run for several hours without a heat sink or a fan.
  • The Via is a VERY low power processor.

    Since its one of the 1 GHz processors in the board, TDP is 5W.

    Depending on what power-feedback is involved, the processor might actually just go "I'm overheating, throttle back" and drop down to say 500 MHz at 2.5W or so. The MPEG decoding shouldn't even take too much power, since the CN700 chipset includes hardware MPEG2 decoding.

    As a bonus, the box is OPEN, which improves the cooling.

    • In open air, with no fans blowing air PAST a hot object, it will cool much slower than inside an enclosure where air is brought to the object and is actively exhausted.

      This isn't readily apparent in most modern equipment because hot components have their own active cooling, and the ambient air is cooler outside the case.

      However, if I turn up my 3-speed 120mm case fans to Max, as opposed to Min, my CPU temperature will drop below what I am able to achieve outside.

      But that is only possible when the wiring has

      • Re: (Score:3, Interesting)

        by nweaver (113078)
        The case fan is on the heatsink. So closing THIS case would greatly reduce the cooling, as hot air would be trapped in the case.

  • My experience with no heat sink (Score:5, Interesting)

    by VAXcat (674775) on Thursday May 22 2008, @09:56AM (#23505456)
    A few years back, I was troubleshooting a problem on my desktop. It had a Duron 800 in it. I got tired of putting the heat sink and CPU fan back on every time I made a change, so I figured, what the hell, how hot can it get in the time it takes to try and boot. It made it through the boot fine. I mused "Works great! I bet it doessn't even get that hot. Wonder how hot it is?" With that thought, I reached in and touched the top of the CPU. It was so hot that it instantaneously branded the text and logo etched in the top of the chip onto my thumbtip, before I could react and yank my hand back. For a few weeks, until it sloughed off, it was readable in reverse on my thumb...taught me new respect for the current consumption & heat generation capabilities of CPUs.

  • /var/log/messages: (Score:4, Interesting)

    by dannycim (442761) on Thursday May 22 2008, @10:16AM (#23505744)
    I've made my home machine almost totally silent by using some really large heatsinks. Up 24/24 7/7. One 12V fan running super slowly at 5 volts.

    If I re-encode a movie I get:

    May 21 07:48:00 ganymede kernel: CPU0: Temperature above threshold, cpu clock throttled (total events = 4742833)
    May 21 07:48:00 ganymede kernel: CPU1: Temperature above threshold, cpu clock throttled (total events = 4742833)
    May 21 07:53:00 ganymede kernel: CPU1: Temperature/speed normal
    May 21 07:53:00 ganymede kernel: CPU0: Temperature/speed normal
    Do I care? Not really. Been like that for 3 years now. When it dies I'll swap it for a less powerful CPU and go totally silent. :)

  • Not a challenge... (Score:3, Interesting)

    by -Neko- (67564) on Thursday May 22 2008, @10:45AM (#23506286) Homepage
    Since when was running a 1 Watt CPU without a heatsink regarded as a challenge?

    http://www.genesi-usa.com/efika.php [genesi-usa.com] - plug plug

    That system runs at 1W@400MHz, although has no video-accelerating northbridge to add to the heat, it can play that MPEG4 video just fine (I am playing something similar now). We've designed it so the 2.5" hard disk actually sits about 5mm from the top of the CPU - if anything we're making cooling harder, and there is NO heatsink. The CPU does NOT power manage into SpeedStep style states - it just runs at 400MHz or "standby" (where it cannot run code until an external interrupt).

    It runs fine. Mine's been on 24/7 for nearly a year, barring moving it around and connecting it up to things like new hard disks, changing power strips or measuring the power it uses. It never overheats.

    What's the challenge meant to be? Just how crappy Via's chip needs to be that it CAN'T run at 500MHz on a 90nm process, and do without a heatsink of some kind?

  • We did this at Transmeta (Score:4, Insightful)

    by Dhar (19056) on Thursday May 22 2008, @11:25AM (#23506926) Homepage
    Back in my Transmeta days, I set up a demo doing exactly this...one of our CPUs playing movies without a heatsink, head-to-head with a comparable Intel and it's (hot) heatsink. It lasted all day, and only got slightly warm. Still, I always expected to get burned every time I stuck my finger on the die top for the reporters. Poor, poor Transmeta. :)

    -g.

    • Re:How about (Score:4, Informative)

      by sm62704 (957197) on Thursday May 22 2008, @10:51AM (#23506402) Journal
      <OT>You really don't need the non-breakable space, but if you would have you got it backwards. The apersand goes before nbsp and the semicolon follows. If there are any spaces it won't work. </OT>

      Will what melt, the CPU, the server, the building, or the polar ice caps?

      Shit, my ice cream cone just melted...

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