Heat Reduction - Your Comments Please

[Patrick Ruane]

Hi guys

I was having a debate with my brother the other day about the best way to keep your processor cool. I've always had my processor fan blowing air off the processor, but he has his fan blowing air ONTO the processor. I'm fairly certain the air has to be blown away, but what do you all think? And have you got any interesting / unique stories to tell about overheating pc's or tips for us overclockers?

Points will be awarded for your comments and the originality of your tips.

Patrick

[Paul R. Dittrich · Accepted solution]

As I recall, the *rate* of heat energy transfer from one mass to another, is dependant upon the relative temperature differential between the two masses.

What this means to me is that for maximum CPU cooling to occur, you want the coolest available air mass flowing over it's heatsink. If the airflow cooling the CPU has already picked up heat energy (gained in temperature) from other components, then you will need MORE airflow in a given time period to remove the same amount of heat energy from the CPU.

My "ideal" setup is fan(s) exhausting warm air from the highest point of the system with inlets for cool air close to the CPU.

Just my $.02

Paul

[Roger Faucher]

Hi Patrick:

I have no scientific reason but I believe you want the CPU fan blowing air away from the processor. This should get the heat into the case where it should be removed by the power supply fan. Any number of auxiliary chassis fans can be used to improve the removal of heated air from the case. Just remember to draw room air into the case low and on the front of the case and exhaust it high and on the rear of the case. Also, it is important not to have open holes in the case such as might be created by removing a PCI card and not replacing the 'blank' to seal the hole created.

Good luck!

Roger

[Alexander M. Ermes]

Hi there.
Just a sample from a different computer company.
These guys have put heat deduction pipes over the cpu fan, which sucks the hot air from the passive cooler directly mounted on the cpu through the pipes to the outside of the box.
Guess why.
Rgds
Alexander M. Ermes

[Jon Finley]

The company I work for builds a hardware fault tolerant unix box. They found that if the air is blown across the processor they were able to keep it cooler than with a fan mounted on top.

(Their findings not mine) :-)

I like: rounded disk cables, cpu fans and chassy fans. Makes for a VERY happy box.


Jon

[Patrick Ruane]

Sorry for delay in assigning points, i was called out of the office for a few days :(

I guess what we can deduce from this is that it's not that important whether the air is blowing on or being sucked off the processor (Thanx paul) but where the air comes from, how cool it is and how well it is carried out of the case afterwards (to get that heat as far away as possible). I guess i'll have to look at each setup as it comes and see how well the case is set up. I've seen a few cases with inlet / outlet fans in the front / back (respectively), might be worth a look for maximum air movement.

As it is this is now a moot point as my clock unlocked processor was in the PC that got stolen from my house last week :(
My only consolation was that the thieves will have fun trying to install the Windows software they took on my Linux workstation ;)