There is no voltage setting for memory rams in bios and it work great on 5-5-5-15 but on 4-4-4-12 wont boot up. In book said 667 and 800. I already did bios upgrade for Pentuim Dual Core CPU in months ago. In new bios setting can do 667Mhz, 800Mhz, 1066Mhz, 1333Mhz, and 1600Mhz.
Only crucial can sell memory rams that can go up to 1066Mhz for my motherboard. I cant find any memory rams will support more than 1066 for my motherboard "DG33TL".