Dynatron H6HG Xeon Nocona / Irwindale socket 604 2U Active Heatsink. (not for LGA771) Fan Dimension 60 x 60 x 25 mm Speed At Duty Cycle 20%: 1400 RPM, At Duty Cycle 50%: 3500 RPM, At Duty Cycle 100%: 7000 RPM Bearing 2 Ball Bearing Air Flow At Duty Cycle 20%: 7.407 CFM, At Duty Cycle 50%: 18.517 CFM, At Duty Cycle 100%: 38.283 CFM Noise Level At Duty Cycle 20%: 2.01 dBA, At Duty Cycle 50%: 35.9 dBA, At Duty Cycle 100%: 48.1 dBA