CPU Fan direction?

[William]

My cpu fan is suppose to move air away from the heatsink, right?

 

[WobbleWobble]

Have the fan blow onto the heatsink.

 

[lobadobadingdong]

try one way and watch the temps, the switch it around, most of the time blowing onto the heatsink is better, but not always.

 

[William]

thanks guys

 

[Sonic587]

Originally posted by: lobadobadingdong
try one way and watch the temps, the switch it around, most of the time blowing onto the heatsink is better, but not always.

This is true.

 

[AyashiKaibutsu]

Generally you have side fans as intake so you would want the cpu fan blowing onto the heat sink so the two don't fight

 

[maluckey]

Even easier is if the HS has a shroud, and the CPU temps matter more than system temps, you should use positive flow, otherwise, negative flow.

There are variables that might affect your decision though, even with a shrouded HS, such as case layout, RAM placement and setup, PSU location and type, etc.

The other thing is that even though a shrouded HS will work more efficiently in reverse flow mode, it will also draw heat off of the Motherbord and related component in the airflow path of the HS. This can raise the CPU temps a few degrees C. while lowering the board, ram, and the GPU temps a few degrees.

Try it both ways, and run Prime95, Hot CPU, and Memtest86. If it passes both ways, then pick th quietest is what I would do.

 

[Blain]

Alpha's are the only heatsinks that I know of that are designed to have the fan pulling air up off the heatsink (aka sucking).
All the other heatsinks that I know of are designed to have air blowing onto them (aka blowing).

 

[MercenaryForHire]

Depends totally on heatsink and airflow situation.

- M4H

 

[Bill Kunert]

Note also that most fan blades have an airfoil shape and will be more efficient running in one direction than the reverse.
Bill

 

[alexXx]

bill you are an idiot. he would physically flip the fan over if he wanted the air to go the other way

 

[xylem]

Originally posted by: alexXx
bill you are an idiot. he would physically flip the fan over if he wanted the air to go the other way

You are right, but you are also very rude, it seems.

 

[Mik3y]

world peace....

 

[Bill Kunert]

Originally posted by: alexXx
bill you are an idiot. he would physically flip the fan over if he wanted the air to go the other way

Excuse me for living. There are people who might reverse the polarity of the leads. My IQ is over twice my age and I'm 65 so not quite an idiot. I just love the way some people address other people when they know there is no danger of getting punched out.
Bill

 

[eelw]

There are people who might reverse the polarity of the leads.

No. Most if not all PC case fans are designed to spin in one directly only. Switching polarity wouldn't cause the fan to reverse direction.

 

[Zebo]

I take sucking or blowing

Lame I know... Anyway blow on HS... suck on radiators.

 

[XxSuNSoOxX]

i have mine blowing out... i ahve a slk900-U on my ic7-g... i did it both ways and found that for my case it was best for the fan to blow air out of the heatsink.. as the heat rises to the gills of the HS my 80mm zalman blows it out to my side case fan for extra air out of my system... and it seem to be running cooler w/that setup than blowin air directly into the hs

 

[Soulkeeper]

there are only a few heatsinks that work better with the fan taking air off the heatsink
usually they are ones with fan shrouds to help consentrate the suction of air through the heatsink fins/pins (like some alpha models)
in conjuction with a side case fan to help remove the hot air from the case this can be a good setup

in most practical situations tho having the fan blow air onto the heatsink is obviousely better

just try both if unsure and compare temps