FrostyTech puts some heat to the Alpha Novatech PAL8942 Socket 478 heatsink.

Making use of their signature cold-forged aluminum construction with an embedded copper plate the PAL8942 is big, black, and chocked full of hexagonal pins. With an aluminum shroud covering the top 1/3 of the pins an 80mm fan can be attached in either a impingement or exhaust manner for optimal cooling. In fact, we tested the Alpha PAL8942 with the fan in both an exhaust and in an impingement (blowing down) orientation and found that there was indeed a slight performance increase with the fan pulling air up through the fins and expelling it out the top.