I have an Athlon64 X2 4400+, OPN - ADA4400DAA6CD. www.amdcompare.com lists the voltage as "1.35V - 1.40V" this OPN decoder: http://www.amdboard.com/amd64_opn.html lists it as "1.35V - 1.40V" also Techpowerup's CPU database lists it as 1.30V. Also most review sites I have seen list it as 1.30V like this one: http://www.lostcircuits.com/cpu/amd_x2-3800 /. Finally, my A8N-SLI Premium with latest BIOS (1009) uses 1.30V if you put Vcore to auto. The Vcore monitor is very accurate because if I set 1.35V in the BIOS that's exactly what it reads in the hardware monitor. Mine is stable at stock at 1.30V so I'm fine there I'm just wondering if anyone knows who is right, if 1.30 turns out to be wrong then I'd like to let the techpowerup guys know and get the list updated, but 1.30 seems like a very strong consensus out there.