I have the Leadtek 7800 GTX EE 490/1250. The heatsink/fan is the dual slot version like the 512 GTX. 92mm I think. I have been looking into the way the fan works regarding heat and fan speed - at default settings the fan stays at a constant speed (75% duty cycle). Using Riva Tuner I can adjust the speed manually no problem. If I set it to Auto in Riva Tuner it sets the speed low but does not increase the RPM as the temp rises. Is the fan on this card supposed to automatically increase/decrease with temperature variation?