[casecutter]

I never ran the XP-90 on my 165, but I bet it would keep you in the mid-high 40's load, and the better the fan the better it works. I used a 120MM fan on it rotated 45 degrees and I could still use the stock 92MM fan clips to mount it. I don't think the Artic Freezer is going to do much more than the stock Opteron cooler, but the XP-90 is definitely worth it. If I remember correctly, my temps on air were abut the same as yours as I was using the AC Freezer 64. The XP90>Freezer 64.