I just copied bigpinkdragon286's answer from another post on Toms Hardware as it explains in good detail. All the credit to him.
http://www.cpu-world.com/CPUs/Bulldozer/AMD-FX-Series%2...
There are at least four different low power P state voltages listed on CPU-World, along with two boosted P state voltages. 1.425V @ 4.1 GHz, 1.4125V @ 3.8 GHz, 1.225V @ 3 GHz, 1.125V @ 2.5 GHz, 1.025V @ 2 GHz, and 0.9V @ 1.4 GHz.
You may be reading the voltage when the processor is in one of it's various lower power states.
I believe the FX-6300 is supposed to run 1.35V when at 3.5 GHz, it's default non-boost, non-power saving clock rate.