You certainly can up the FSB. A friend has an 850 that is overclocked to about 977 by upping the FSB to 115. You should be able to get 100mhz out of upping the FSB easily. Additionally, if you are just going to do a mild overclock (<150mhz) upping the FSB will yield better results than changing the multiplier. My Duron 700 runs faster at 825 (7.5 x110) than it does at 850 (8.5x100). You probably should experiment with some different combos to see what the best result is. But, if you don't want to mess with a pencil or conductive pen, upping the bus will work quite well.