I wanted to wire my CPU fan in such a way that the speed of it is not controlled by the MB depending on the temps. I wanted to connect it right to the 12 volt connector pins. I was wondering if this would work...

Get 3 wires, 2 of them to go from the CPU fans Yellow and Black 12Volt wires, and connect them to the 4 pin connector wires matching Yellow and Black on it. The third wire would go from the CPU fans green wire to the proper pin on the MB to still be able to get a RPM readout.

Under normal conditions my fan spinds at 3500rpm, ive seen it get just over 6000rpms and would be nice to spin near that all the time.

Does the MB supply the CPU fan with more than 12 volts to achieve 6000rpms?

Also where is the "Case temp" sensor on my motherboard

I have a ASUS P4T Socket 423 i know its around the green LED on the motherboard.

Well i did the test myself, and found out that from 12 volts it spins at 3500rpm, it only achieves 6000rpms if the MB increases the voltage. Also wat is the 6 pin connector that goes onto the MB for? I forgot to clip it on when i started it back up and everything still ran perfect, wondering wat it does than.