A few bios updates ago, I noticed a relatively dramatic increase in the temperature of the CPU (previously ~35° idle with stock intel heatsink/fan, now around 43°) and some performance problems. I've wanted to get a better heatsink anyway for some time now and was looking for recommendations. It seems that the Hyper6 performs well (I'm not overly concerned with the noise), but thermalright and others have a few that look as if they perform decently. Are there any major differences between the SLK-948U, SLK-947U, SLK-900U, and SLK-800U? Thanks.