I am trying to set my pII 300 sl2yk to run at 450mhz. I have a p6f91i version 0 which does not support b21 override directly. However i read that the factory test jumper jp10 is b21 override and i would have to clear the cmos. I did it and i stil ldont get 100mhz. what else should i do? upgrade the bios?