1) May try the Lenovo Fan Speed Control Driver for your m92p. *That one may not fit your PC. http://support.lenovo.com/us/en/downloads/ds008774
2) Try update the intel chipset driver first. https://downloadcenter.intel.com/download/26132?v=t
after that run the speedfan again to see the software can recognize the fans or not. Because the MB needs the newer sensors driver so that the speedfan can detect the fans. If it still can't not detect the fans, you have to buy the fan controller, if you want to control the speed.