MSI is one for the overclockers, they have been in the past and the K8N Diamond Plus is once again. MSI uses the AMI BIOS for its boards. While good, we have found Award BIOS to be a more tweakable BIOS setup, but each to their own - MSI has used AMI for a while and it seems to work for them.
Once you enter the BIOS, you need to visit the Cell Menu section in order to gain access to all of the overclocking features. First on the list is AMD Cool'N'Quiet. When this is enabled, Windows is able to lower the CPU multiplier and voltages when the CPU is at idle, this allows AMD Athlon 64 CPU's to run much cooler and consume less energy in their idle state.
Next is Adjust CPU FSB Frequency option. MSI gives you settings from Default of 200MHz up to a max of 450MHz in 1MHz increments. While 450MHz isn't obtainable these days, it's still nice to see this option available.
Next is a sub menu called AMD Overclocking Configuration. In this menu you have access to the Hammer FID and VID options. FID gives you the ability to lower the CPU multiplier manually, or raise it if you have an Athlon 64 FX series CPU. The VID function allows you to override the CPU default voltage to give the CPU some extra juice.
You can adjust the CPU voltage from 0.08v up to a max of 2.15v in 0.05v increments. To get this high you need to run the extra overvoltage option. DRAM voltage range extends from 2.5v to 3.2v in 0.1v increments. Northbridge and Southbridge voltage ranges from, 1.2v to 1.8v in 0.1v increments.
Using all these features we managed an FSB of 358MHz with our CPU at 4x DRAM voltage a 2.9v, CPU at 1.55v, Northbridge and Southbridge at 1.4v. Overall we were impressed with the stability and overclock-ability of the K8N Diamond Plus.