Just wondering, I've seen people talking about installing a circuit which keeps the case/cpu fans running for a length of time after the comp is shut down. Sorta like a turbo timer for a car. Is this worth doing ? Is there really any benefit to this practice ? I understand that the heat generation should stop immediately after the power is shutoff, but will the heat hang around for any length of time ? Main reason I am asking this is because my current project is mainly aesthetics, and I'm looking for some practical mods to so with it
when you shut off an oven, is t immediately cool? I dont have a heatsink in my system, as I run watercooling. Though, even in my system my pumps are rigged to run at all times regardless if the pc is on or off. I like this because running at 2.7ghz really heat things up, and having the heat slowly removed even after it stop producing heat should really help.
their is a lot of debate over wether or not there really is anything it is doing to help. Morphine made a good example,(not trying to be belligerent) except the fact that an oven is many thousands times larger than a chip, and it gets hundreds of degrees hotter (also in debate with those overclockers ). And how many ovens have huge heatsinks on them? If you had a heatsink equivilant on an oven, it would be about the size of a house. Does an oven cool off immediatley, no, but no more heat is being made. Just like a chip. Unless your heatsink is running hot to begin with, the heatsink can passivley cool the chip itself. There is no hurt in keeping the fans running, however. If you are running a watercooled rig, then i can see an advantage as there is little heat exchange done via convection or passively though the air with a water block and no moving water.
Well if you put a heatsink on an oven, that would defeat the purpose of making a hot box and turn the oven into a radiator/space heater. That aside... The instant your comp is off, the processor cools down a lot just because there is no longer a heat source. And unless you're running 8 raptors and a 6800ultra, the proc is the mean heat source (which would also cool near instantly, but of course not to room temp) Put it this way... once the computer is off, temperatures only go down inside it (unless you're running some bizarre vapor-case-cooling setup). Keeping fans running just cools it to room temperature a little bit faster. Personally I think it's pointless, but if your computer is only off for very short periods of time the time when everything is cooler becomes somewhat more valuable. But figure that if products are within temperature specs, it should have no effect at all.
Well I did a lil experiment with an old cpu a lil while ago. It may sound crazy but it convinced me. I used an old p1 233mmx chip a fiew months back and booted it withought a heatsink while having my thumb over it and no heatsink. (yes u heard me rite bare finger on core). Needless to say the chip got uncomfortabl hot within seconds and then started hurting at that point I shut the pc down. The chip itself cooled within a fiew seconds of power down to a barely warm status. The point im trying to make is that seeing the size of the heatsinks on todays pc's when the pc is shut off the final revdown of the fan should be enuf to cool the cpu down to resnenoble temps. I personaly see no point in having your fans on when the heatsource is eliminated. just my $0.02
Just a small thought which might be wrong, but isn't it more the change of temperature rather than the constant temperature which harms things (under a certain level of course- 70c ish)? Surely trying to cool it faster may not be doing it any good at all? But then again, if it's an expansion/contraction type thing which causes the harm, then it won't cause hardly any problems
And you don't have to worry about that if you leave your PC on 24/7 I find that thing useless, I can even go fanless with the PC on, creating a lot of heat, so imagine when I turn it off and that heat source is no longer there. If you have a good HS, if your temps aren't high while the PC is on, then I don't think you should even think about those circuits that keep your HSF on for some seconds/minutes.
No. Contary to popular belief, an overheating processor doesn't melt, the added heat screws up its electrical properties allowing/forcing too much electricity to flow through it and blow transistors. In fact, silicon doesn't melt till around 1200*c which is even beyond prescott without a heatsink (or even the wrong side of a pelt as a heatsink) Computer parts are designed to have changing and/or high temperatures and whatnot be safe for them, so I couldn't imagine it being a problem.
The thing is that silicone is tempered like glass in fact it is very clean glass. The only problem would be if you have suden changes in temps such as going from 100c to 10c would hurt it physicaly (brobly a crack). and also the thermal conductivenes of silicone is superb being almost a crystal. I dont see a reson to keep the fans on during the OFF period of the pc unless you plan on rebooting it very quickly at witch point the fans kick in regardless and the pc stabelises heat once again. The only usefullness is if you have a thermal exchange unit such as a promie at witch point your trying to get the liquids cool enuf to run the chip at the overclocked speed you chose. Even watercooling would not be of any help in being on after the pc has been shut down or before the pc has powered up.
ok, we have gotten WAYYYY off topic. We are talking about wether or not fans on after shutdown would be benificial. Benificial - not really, but it cant hurt. Nack to off topicness. The remark about wether orn ot the core would crack is irrelovent. A cpu cool and heats constantly. And whenver you turn off your computer it coold sown. If you turned your computer on and waited for it to get to almost thermal shutdown, and then threw liquid nitrogen on it, then yes it will crack. Thats why refridgerant style coolers have to be so cold to start the comptuer, because it will cool so FAST. Hence fanst. compared to a lightspeed, a heatsink is not a fast cooler, so there is no worry of your core cracking unless youve gone from off to on about 10 thousands times to the point where it actaully BECOMES brittle. We are talking about processors and cooling them. Morphine made an example of a heat source without a cooler, so it was not an excellent example of a cpu. It was like comparing apples to oranges. A cpu has means of removing heat, an oven does not.
The processor only generates heat when the computer is on. Because it is generating heat, it needs some way (a heatsink) to remove the heat. Once the computer is turned off, the processor is no longer generating heat. If it is no longer generating heat, NOTHING is getting any hotter. The processor, as well as the heatsink (or water block, water, radiator) are only getting cooler. If your processor can handle the heat generated when the computer is on, it can definitely handle any heat leftover once the computer is turned off. In summary, there is no real reason to have the fan, or pump run any longer once the computer is turned off. If your processor runs extremely hot for some reason, running the fans or pump after the computer is shutdown may help a tiny bit with the life of the proc. Remember, the expected lifetime of processors is pretty long compared to how often it will be upgraded and replaced. Also remember that processors can handle quite a bit of heat. I think his has been said by a few people, but it can't hurt to add my opinion.
i think it depends on your heatsink as much as it does your processor ... i can see a stock AMD heatsink passively cooling a just-shut-off chip safely, as it is made of aluminum ... but my hunk 'o copper (tt v7+, heavy solid copper fscker) will probably retain the heat quite a bit longer and without airflow may very well actually raise the die temperature after shutdown ... thing is i just dont know, cause ive never shoved my finger in my hsf after shutting the puter off.
it wouldnt hurt, but it would be cool it wouldnt hurt the processor, and i cant see any advantage in having it, once the processor is off, it will cool down, albeit slower without a fan than with one. it would be pretty cool though to have a pc that "winds down" when you turn it off (and "winds up" when turned on), kinda like power off, then hear the fans slowly slow to a stop, maybe a capacitor inline with the fan could do this? (im not an electronics dude, ask someone before trying this). so when you turn the pc off, the fan runs and as the capacitor discharges the fan slows until it stalls out. conversely, after thinking about it, i would presume the hottest time for your processor is immedeately after turning your pc on, im assuming loading an operating system will run your processor at 100%, and the fan has just started, and the hsf is at room temps. it would be cool to have the fan spin up before the processor turns on, kind of "press power button, fan spins up from still to full rate in 5 seconds, then pc comes on" and reversed for turning off. sort of a pre-cool and post-cool for the processor. just a thought.
i believe frozencpu.com has what your looking for. http://www.frozencpu.com/cgi-bin/frozencpu/bus-12.html hope this helps
Nice gadget...I was planning on building mine for about $5 You guys have changed my mind Not planning on doing this mod anymore. The hardware I'll be running wont be running very hot, although it will probably be running almost 24hours a day, which makes the timer pretty useless as it'll never be shut off
