Which way should the cpu heatsink fan blow?

[shochu]

Might be a stupid question but should the fan face "down" and blow into the heatsink or should it face "up" and blow away from the heatsink. Seems like "up" would draw hot air away from the heatsink and "down" would blow cool air over the heatsink. Which one is more efficient? (yes ... I'm too lazy right now to test both set[ups hehe) Also, I'm at work so can't do any testing now. Thanks!

 

[Tiamat]

Welcome to the AT forums, I hate to say this, but your thread has been posted by others countless times.

For most brand HS, the fan points towards the mobo for better temperatures. For Alpha branded HS, the fan points to the case side. Difference in temp for mounting the fan correctly could be as much as 6C in my experience