Hey, I just looked at my BIOS pages and I don't see much for overclocking this Iwill KA266-R, just memory (FSB-DDR) speed and Vcore. Multiplier is by jumper. After reading the mushkin information, I'm confused because my 2/15 bios doesn't have those options. Anyhoo, I'm currently trying:
Vcore = 185, Memory 140MHz, 10x on a 1.2GHz Athlon.
Have about an hour of Quake3 doing good.