Our sources confirmed the voltages of the upcoming Barcelona and Agena FX K10 parts. The stock voltage for the top K10 CPU clocked at 2.5 GHz is 1.328V. Some low voltage models will work with 1.276V.
Currently the fastest 90 nanometre part, FX-74 at 3 GHz needs 1.35 to 1.40V to work. The first K10 part to launch will be codenamed Barcelona and its native quad core actually needs slightly less volts than the current dual core design. This is quite a success for the first native quad core, even if we are talking about a 65 nanometre chip.
The 1.328V is necessary for 2.5 GHz clock for all four cores. That is what Agena FX and Barcelona is made up from.