smoke will sprew out of the ddr2 ram slots and your northbridge will blow up and destroy your computer......sike....no nothing will happen. You will just end up ocing your fsb . Might get your northbridge alittle warmer than normal depending on your setup.
Can you run a 1.9V ram stick with a 1.8V ram stick on a 1.8V motherboard?
i have no idea. my motherboard(gigabyte 915g duo) supports ddr2 533/600 and ddr1 400/333 ram. the manual says if u want to run ddr2 600 (not 667) ram then u have to run 800fsb processor and overclock in bios.