Air flow direction

[enginjon]

I have a new socket A Athlon 850, and I'm using a standard ballbearing hsf that came with it (rated for use with up to 1.2 ghz). Anyway I always thought that the fan was supposed to suck the air away from the heatsink, but the way that this hsf is setup, it blows air down and through the heatsink. Which way is right, or does it matter? Is one way more efficient than the other for better cooling? And no, i didnt just connect the fan improperly, the curl in the fan fins is to blow down. The reason I ask this, is because a I have a case fan (80mm) on the back of my case, exhausting air out, and it is only a few inches from the hsf, so that case fan is "stealing" the air that should be passed through the heatsink. I have the case fan mounted in the default spot in the case (nicely pre-drilled mounting holes and grill) Any thoughts?

 

[Spoooon]

Certain heatsinks (PAL6035, Hedgehog) perform better with the fan set to "suck" and the use of a shroud. That forces air to travel through the bottom of the heatsink to the top and out. All others pretty much perform better with the fan set to blow on the heatsink. I tried flipping the fans around on my old Slot A HSF. It performed better blowing on the heatsink.

 

[Packet]

actually, what you have set up is good, provide you have proper setup in the front of your case.

The exhust fan in back, is going to be sucking all the hot air away from your CPU, cooling it down.
What you need to have, is a fan blowing cool air in at the front of your case. This will cause the air going to the CPU to be a steady cool flow.