Speedfan goes farther than my ASUS BIOS and other software for controlling any sensors it finds, and it finds them all.
My only problem with it was that it caused my system to crash just once, and that was once too many. I offered to help the author and programmer via e-mail -- didn't want to be automatically connected to his web-site -- too many of those situations to manage. But haven't heard back from him.
I was still impressed with it. Like Ron Popeil says about his counter-top rotisserie -- "Set it -- and -- forget it."
I just don't want to forget it and then have some glitch leave my fan setting too low, whereupon the system gets fried.
But if you're staying in the vicinity of the machine, it's really, really a nifty program, and the simple visual interface understates the power of the program.
Also, I think my crash may have been caused by activating the graphic display and switching between the voltage and fan speed displays. I think if you are more careful about how you use it, it is probably pretty stable.