Appropriate cooling of the CPU core is the #1 issue when it comes to overclockingsuccess -don't let anybody tell you different ! Electronic devices/circuits is in general not very happy with temperatures exceeding 35*degree celsius. The goal is to keep temperatures below 35*C - and the lower the temperature - the more stable a overclocked system will be. The definition of a stable "cool" system is a system where CPU internal temperature don't exceed 35* under hard load - such as running CPUStabilityTester for one hour. This is with a normal indoor temperature around 20-22*C..... If you can't keep temperature as low as this you don't have a "cool" system. A CPU is a high quality component and can work under temperatures exceeding this -and still remain stable. But if you experience random crashes/lockups - and you as "usual" blame it on Window's instability - you might have a heat problem instead......In real world you will only be able to achieve a "cool system" using solutions as the VapoChill...or using peltiers ...
Check that your CPU core/slug and heatsink is perfectly flat - if not - make them flat ! Done by plane gritting / lapping.... You don't need to be a qualified mechanic to do this. All you need is a perfectly flat glass plate and some fine emery paper. If you feel insecure "how to do" ask a mechanic at the local garage and let him do it for you. Work your way down to grade 6000 paper - and when you are finished the core shall be like a mirror. I did this on a Slot1 C366A - I actually ended up breaking through the chrome color and ended up with a brass coloured core instead.. Before I did this I could run it at 458MHz - after lapping it - 550MHz....A couple of hours work and almost 100MHz more..... We have made a short how to do - here !
The standard heatsink fan that comes with Celeron,PII and PIII is actually a good fan/heatsink combo and can be used to a certain limit for overclocking purposes.The standard heatsink comes with a thermal pad instead of thermal grease, and to improve heattransfer this can be removed and replaced with thermal grease instead.
The market is flooded with different types off coolers - some good some not so good...... During my time with Slot1 I have used coolers from different vendors but I have the Alpha coolers as my favourite - they are a bit more expensive than the others. Alphas delivered by 3dfxcool use another technique than most off the other Alpha suppliers do : they blow air through the cooler . This has the advantage on several types off motherboards that it cools down the chipset who is placed under the cooler itself. This method with pushing instead off sucking is only used by 3 dfxcool's Alpha as far as I know.
A relatively new way off cooling is the use off peltiers - A thermoelectric (TE) cooler, sometimes called a thermoelectric module or Peltier cooler, is a semiconductor-based electronic component that functions as a small heat pump. By applying a low voltage DC power source to a TE module, heat will be moved through the module from one side to the other. One module face, therefore, will be cooled while the opposite face simultaneously is heated. It is important to note that this phenomenon may be reversed whereby a change in the polarity (plus and minus) of the applied DC voltage will cause heat to be moved in the opposite direction. Consequently, a thermoelectric module may be used for both heating and cooling thereby making it highly suitable for precise temperature control applications. For "in depth" information and every thing else you want to know about Peltiers please visit FerroTecAmerica .
Word off advise regarding peltiers: it will be very "inconvenient" if your fan stops --- the peltier don't stop heating up your heatsink..first thing that happens - after a minute or so - is that your CPU is destroyed since the heat can't dissipate and the peltier will start heating instead off cooling your CPU . And the worst scenario can be a fire inside your computer .. So if your house catches fire and the peltiers/ heatsink fan isn't "approved" -- you have a problem with your insurance company ...NEVER LEAVE A PELTIER BASED HSF SYSTEM RUNNING WHEN YOU ARE AWAY... I have tested this with a 70 Watt peltier element in our testrig and when I stopped the fan it took less than 4 minutes and the fan were about to start melting .. I stopped the experiment then... The majority of peltiers won't be a firehazard - most of them will selfdestruct before they get so hot that a fire occurs. I don't recommend peltiers below 50 watt's so you must also ensure your power supply can deliver this.. Also see the monitoring chipset temperature further down regarding temperature monitoring off peltier's.
The most "messy" way is to put your motherboard in mineral oil (which is non conductive) and circulate cooled down oil -the adcvantage with this is that you actually cools down everything attached to the motherboard such as chipset,graphic cards,pci cards aso. Such a system is complex since you need a heatexchanger - or peltiers or likewise to cool down the mineral oil.
One off the oldest way is water cooling which is used on "supercomputers" often used by the goverment/military - here you also have the same problem with condensation and besides that you will need a water tank and circulating pump and a cooler and peltiers or likewise to cool down the circulating water. I saw a guy who placed his water tank in a freezer ( AntiFreeze must off course be added to the water) .... Personally I think this method is too much off a hazzle for a home user.
Super computers also use liquid nitrogen for cooling. I know one private person who does this - but he has very good knowledge about this. There are a numerous dangers off so extreme cooling and I will not recommend anybody start playing with such a method - besides you can't buy liquid nitrogen in the shop on the corner.....
As far as I see it there are only one / safe way to go for us who want's more than conventional air-cooling. And that is to buy ready readymade cabinets with cooling compressors built in... There are two companies that deliver such systems : Asetek and Kryotech. Where Asetek delivers the best solution which also outperforms Kryotek in tests. Asetek deliver kits / adapters so you can use the most popular CPU's with them - support of dual processors is upcoming. And surprisingly it's not so expensive as I tought ! Asetek will deliver conversion kits for upcoming CPU's too...
Conclusion : Alpha make some off the best coolers - and at a reasonable prize. But if you want more cooling than the Alpha can deliver - I would advise you to skip peltiers and jump right to the Asetek solution. If you are willing to hand out the money for a peltiersolution you probably want more than the peltier solution can deliver after a while anyway..... Peltiers will probably be a thing off the past as processors go over 50Watts - if peltiers is gonna be used thereafter it will be in combination with water cooling.
What's the catch : Noise and heat (except for VapoChill ) - but you can do a lot with this yourself - buy insulating mats and cover the inside off the cabinet. Place the cabinet/tower under the table. For the fan's on CPU coolers you can relatively easy build a air-duct and insulate the inside off it to lower noise - Here .
Important : If the CPU fan option is available in your bios : under "Power Managment Setup" make sure the option is set to "always on" default is "suspend-off"... Picture
VapoChill outperforms Kryotech and can be delivered with adapters for PII , PIII , Celeron slot1 , Celeron S370 (includes slotconverter) and AMD's K7 processors. A dual system is under development. Visit our VapoChill section
Software Related Cooling:
Do they work - or not ???? YES - they work - more or less .
Waterfall - it's free and - does a excellent job ! In the downloadsection !
Cooling that MoBo Chipset:
Have you ever looked under the chipset heatsink on your motherboard - is it thermal grease or at least a pad there ? Probably nothing whatsoever ! Take it off immideately and add some thermal grease - improves heattransfer considerably ! And if the space permits - feel free to install a better heatsink with a fan attached. 3dfxcool's microfans is perfect for this purpose. The surface off the heatsink chipset is probably very coarse like this picture - we have lapped in ours so they look like this . If you have a 20 - 30 w Tec (peltier) and the space permits - you can use it for cooling down the chipset. You have to make a hotplate at the same diameter as the chipset and ensure that you do a proper insulating job.You can see a pic here off the one I use - the pic is from the testrig and you can see the temperature here in action after 1 hour ( ambient temp.24'c) Here is another way we use when we test peltiers effeciency ( we used 1/2 a liter 70' water at this test - the pic is taken after 10 minutes - 52Watt peltier ) Because off my rather bad experiences with peltiers I would advise you to use a monitoring device / switch to control the temperature. See more on this below here.
I'm using a rather cheap temperature watch which have two poweroutlets and is supplied with external thermal probe. As you can see on the picture you can read the temperature in front of the cabinet. It gives alarm when it reaches desired set point. It can be bought in Norway and Sweden by Claes Ohlson part# 32-1019 If you are gonna use a peltier - this is a must have and a cheap insurance in case your peltier fails...... Another advantage to have this temperature watch is that you don't have to run a motherboard monitoring program which also uses resources.This unit can off course monitor temperature at any desired point - and the external cable is pretty long too.. In the US this temperature watch is sold by Cyberguys and they call it a digital doctor :) (thx Eric)