I got a 80-to120 mm fan adapter from svc too. I am using the stock AMD heatpipe HS on my Opteron 165 @ 1.5v. When I replaced the stock 80mm fan with a 130mm Thermaltake Silent Wheel (54 cfm 1400rpm), the temp went up to 32c idle and 53 prime vs 27c and 48 prime with the stock fan. I tried it with anther 120mm fan and got the same worse result. Strange. I am back to using the stock fan.