http://www.amazon.com/Delta-TFC1212DE-PWM-120mm-Speed-Sensor/dp/B008NZSUPQ/ref=pd_cp_pc_2
i put it on the back and its running full speed.. its not doing pwm.
edit..
so after checking around, and plugging this fan into my motherboard with the molex adapter and pwm on the board.. it seems this fan has an inverted pwm controller.. 100% is 0 and 0% is full speed..
im not sure if this can be switched in the software of the s5.. or any other way.
You can swap those pins on the connector very quickly. Get a needle or similar and push the pins out of the connector, swap them over. Its the slot on the 'side' of the connector you need to push into http://p.globalsources.com/IMAGES/PDT/B1000665905/Center-Crimp-Type-Terminal-Housing-Connector.jpg.
swap what pins??
i dont think swapping the fan pins will have the effect im looking for.
Sorry, you're correct, I misread what you posted initially. I though you meant the PWM and sensing wires were reversed.