Hi, Gary > With 2 TwinMOS Twister PC3200 CL2 256MB DIMMs the motherboard freezes. > I'm currently using 2 old 256MB PC2100 DIMMs in it. Yeah I exactly see same symptom. Opteron prefer its favorite DIMMs. Be sure to use `recommended' DIMMs. Opteron has direct memory controller... I changed my DIMM twice. Regards, --maho