Quote Originally Posted by ORVILLE View Post
My Gecube PCB is slightly different to most others. It does not have the resistors that are used for most other pencil mods. As well as that, bios voltage mods do not work for this board (deafult always stays 1.25v in both 2d/3d).

Anyhow here is the pencil mod that works for me. BE WARNED - do not reduce the resistance too much - one or two strokes of a 2B pencil is enough and always use a volt meter. My first attempt ended in 1.76v being fed to the GPU.

Default Resitance OF 2.44K gave me 1.25v and 770Mhz limit
Modded Resitance at 2.2K gives 1.42v and 877Mhz Crysis stable
Hey man, I think I have the same card (gecube 512mb 3850 x-turbo III). Do you happen to know why you can't change voltage through bios? Do you know if a different brand bios will work to change voltage? I just hesitant to try pencil mods, but might give it a shot if all else fails...