My laptop's Sempron Mobile allows me to go as low as .8 V with RMClock. Of course it's only stable at that voltage when I'm running it at the lowest speed of 800 Mhz. 1.1 V is stable at 1.6 Ghz though. It's much better than the 1.45 V and I barely hear the fan.
I tried cpuid and it works fine in my old pc but my new one won't change in windows although maby my bios has some tampor resistance or something, I dunno but it will let me change mutliplier in windows but not voltage.