Well a core has an architectural limit regardless of how much voltage it can handle, if you could modify a core somehow to take upwards 3vcore it would still probably max out about the same as other cores at much lower vcore settings simply because the silicon engineering can't support the higher clock speeds
Are you kidding? At 1.525v, I can overclock my 165 by 1GHz prime stable. ANYWAY, I wouldn't go much higher than 1.6v on dual core.
That is a rare exception though
My Opteron doesn't wanna go past 2.65Ghz right now and I've stopped for now until I wait to get it under water...core 1 is still very capable and could keep going and going but core 2 doesn't wanna do 2.7GHz regardless of how much vcore I give it, if this was a single core, I wouldn't have to worry about core 2 at all and could just keep going and going