I am about to build a system with a Centurion 5 CAC-T05-UW case, and was considering Zalman CNPS7700 CPU Fan. This fan looks like it will fit beneath the Cone Shaped side vent and either blow out or suck in from that vent, which as I say, has cone shaped attachment. One thing that bothers me is that the MoBo has a 4 pin CPU fan connector, the extra pin is for fan speed control and this and most other CPU fans I see only have a 3 pin connector. Why is this..??? Am I missing something here..??