Yep. It should not harm anything. The voltage the CPU is made/specified for is the Voltage where it is guaranteed by the mfg. that all transistors will shift and switch around. If you lower the voltage the power consumption will drop (I forgot the damn formula with frq. and voltage), without a loss of computing power. What can happen is, that not all transistors will switch and so you will get more or less severe errors. It is a matter of experiment but one should try to set the lowest specified voltage in every case, that should be safe. If your own CPU was produced on a nice day you might be able to go lower, if it was produced on a rainy monday... well. Not much capacity in undervolting.
Originally Posted by chefkoch
Please note that not all BIOSes are genius and so if your box hangs after underclocking or undvervolting (or over~) you will have to reset the BIOS/CMOS by jumper so it will forget the settings a go back to failsafe defaults.
Some errors will not happen during P.O.S.T. but later when the OS kicks in or if you just stress your CPU. Then you can enter your BIOS setup and regulate the setings back to a safe position.
more on topic: @ kbios
If you ever happen to have some spare money, that thing was 35 Euros, in case you live e.g. in the US it should be cheaper (all electronics is more expensive in Europe, don't ask me why).
Though the boxed coolers aren't that noisy, esp. when you put them to a regulated fan port so it will regulate fan speed according to the temp. sensors. And a phenom cooler should always have the capacity for Athlons.