trying to set 3;4 divider in bd7II bios

when i try and set the3\4 divider in bios & reboot,it hangs-long beeps.i have to power off sytem.ram timings are set by spd.should i start out at 100mhz before i set the 3\4 divider.thnx.

I can get as far as 150 cas 2.5, 6,3,3 2t on my board with Corsair PC3000 with 3:4 memory settings.

Suggest starting close to specs with your memory...I.E. 333, ect - using the fsb \3 *4 formula to determine memory speed (150 divided by 3, multiplied by 4).