Under-Voltaging:

So it's on you to reduce the energy-consumption further by decreasing the VCore on your board. Not all boards do support this feature, so make sure your board supports it.

The Athlon II 245 went down from 1.4250V to 1.1500V. 





Of course we run stability test with Prime95:




The Athlon II 240e went down from 1.2500V to 1.0500V. Not that much, but still impressive.