My only question is why would you want to overclock a AMD X2? You mine as well have spent more to get a FX-60, no offense but I really don't think it would give you any better performance.
You know I should of spent that $1,000+ and got a FX-57 instead of $212 for my Opteron 146, I would of had a slower chip and $800 less but I would be way cooler for it, right?
Also VittorioCole, if you want watercooling don't get a crappy ThermalTake kit, If you must get a kit get a koolance, they have done well by me. Otherwise Dangerden and Swiftech make the
best watercooling equipment. Overclockers.com forums has some awsome writeups look there.
Anyhoo, under BIOS MSI put all the overclocking goodies in the "Cell Menu" on that board if I am not mistaken. In that menu
you must disable dynamic overclock if you want to OC it yourself.
I dont like MSI boards so this is all from memory of the last K9N SLi board I set up, if anything seems off just look around the BIOS.
Go under CPU configuration in the Cell Menu and set your multi to it's lowest settings, leave the voltage alone for now.
First lower your HT multiplyer to it's lowest settings (under the C51 PCI-Ecpress menu). The LDT(AM2) to C51(NB) is the setting you are looking for.
Set your memory divider low (400MHz). And under the Cell Menu start upping your CPU frequency slowly, boot to windows and run a quick superPI test, get the dual core version. As soon as it crashes knock your CPU frequency back by 5MHz, You have just found the max frequency at stock voltages. You should really read up on stuff before you start dumping more volts into your cores.
Move the divider back to stock speeds keeping note that you are now overclocking the memory speeds.
Bump your HT multi up be sure you do not exceed the stock HT speed or you
WILL DAMAGE YOUR MOTHERBOARD, NO KIDDING, THIS IS NOT SOMETHING TO IGNORE. Keep in mind HT Speed = HT Multiplyer * Your new CPU FSB. Again do not exceed stock.
There is a awsome generic overclocking FAQ on overclockers.com forums that will explain the reasons behind what you are doing. Please read that first. I will not take responsibility damaging your system, do not take what I wrote as any thing but my opinion on how it should be done, I am not an expert. Read up on it before you take the plunge.