When Overclocking my Radeon 9800pro......

[oulooool]

I was just curious I use Rage3D to overclock my Radeon 9800 pro 128. Now when I adjust these settings in windows(using Rage3D {overclock}) should I adjust the voltage in the bios as well? I mean it's defualt is 66 but I can raise it to about 72 maybe a bit higher haven't tried it yet. Should I just raise one and not the other? Or raise them both accordingly? Thanks In Advance