Everyone here who has been around long enough to know me, knows I have been around awhile. I have always recomended Motherboard Monitor as a utility for monitoring system temps, voltages and fan speeds. Well... NO LONGER!
I had someone tell me that they use
SpeedFan for this stuff, and that it does a whole lotta other cool stuff. For instance, it can change the FSB speeds on some motherboards (but this isn't the main function of it), it can change the fan speeds (making your PC quit sounding like an Apache helicopter), AND you can program it to take over all fan speeds that are plugged into the motherboard, and it varies them according to the temps of your CPU, PWM (chip that controls fans and such), GPU, HDD, or case (depending on the features of your motherboard and video card).
This means the world to me, because one of my computers has 8 fans in total, and it gets very loud. Although SpeedFan cannot make that PC quiet (it can only control fans that are plugged into fan headers on the motherboard) it has definitely helped it. But my other computer has watercooling and only 4 fans total (2 on radiator, one on the chipset NB, and a 120mm in the power supply) and it is completely silent when I am not gaming or editing video. So give it a try, and if your motherboard is capable of controlling the fans, you will not be disappointed.