cpu fan

do i want the cpu fan blowing down...or blowing up pulling heat away?...lol i always forget and get mixed up

 

up of course...
enuff said.

 

are you sure? I remember getting this mixed up a long long time ago and i melted an amd core.

 

Usually it makes no difference,The most important part of the heatsink is the middle,when the fan is sucking,the outside of the fan is doing the most work,so the air don't really come close,when blowing the g-force forces the air to the outside,away from the middle so the effect is the same,the air the fan is sucking or blowing is much more important,it has to be cool air,so make sure there is some kind of cold air flow near the heatsink.

 

I agree with Rikky. However......there are a few exceptions. Some machines (such as a Sony Vaio I have), have the power supply fan (which is exausting out of the case), situated so the power supply fan is right in front of the Processor fan, and only an inch away from it. So in that case, they have the processor fan blowing AWAY from the heat sink. Because having it the other way, would make it fight against the power supply fan. So in special cases like that, you just want to make sure you aren't deterring any air flows.

 

I suspect it depends on the design of the heatsink.

That said, every finned aluminum heatsink I've seen has the fan blowing air into the fins.

If the fan were reversed, I'd be concerned that the air sucked into the fan would take the path of least resistance -- which would not be past the base of the fins, where most of the heat is.

Rikki is correct in pointing out that the outer part of the fan blades generate a higher airflow. But that air is moving at a higher velocity than the air entering the fan, so will be more reluctant to change directions. It is therefore more likely to maintain a reasonable air velocity at the base of the fins than sucking air out of the fins. The fan sucking air out of the heatsink will draw most of its air from the tips of the fins, not the bases, leaving the heat with a greater distance to travel within the heatsink before it can be removed by the airflow

But try it both ways, and let us know the results in terms of your CPU temps.

 

i think it should be blowing air onto the heatsink. but its easy to find out. just try both positions and one will give u lower temps. but if ur suing a cpu duct then sucking the air wont make no sense

 

The air flow always stronger than the air pull out, like RobM said it depend on heatsink.

because hot air always flow up if your fan is strong enough to pull it up.
The good way I like is modding more fan for hyper6 CPU heatsink one fan flow into heatsink and one fan pull the air out then the back fan case will pull it out of the case too.

 

I have a big alluminium heat sink on my AMD, the fan is BLOWING air into it and out both sides, the back case fans draw the heat OUT of the system, My PSU has no underside fan to get in the way. so thats how mine is set up, is it different for other machines ? i have no idea lol, all i know is mine works like that and its only on half its duty cycle as the alarm hasnt kicked in and its running at 43C (cpu i mean)

 

In my way like this but I am not sure it can help you or not, with 2 fan 5000rpm put them at two side of heatsink one blow and one pull out put one plastic piece on top for air heading always go through heatsink.

here is review of hyper6 :

http://www.frostytech.com/articleview.cfm?articleID=1568