I just installed the "D" version on my X800pro. It has the memory sinks and dual heatpipes. I have the optional fan wich comes with a rudimentary speed control. I hooked the fan into my rheobus so I can just turn it up and down as needed. It does an excellent job, I don't have exact specs availble right now, but my temps dropped significantly from the stock hsf. I highly recommend the fan option unless you have excellent case airflow and don't oc. Than fan is virtually silent at the lowest setting.