Even if you set it to that, it wont be running at that voltage all the time, it should only use what is required. it depends on your BIOS settings though I guess? Your voltage setting is probaby different from my "CPU-Overvoltage" setting.
I know with Auto on my CPU-Overvoltage settings that It will only go up to 1.45v at any speed, not letting it go up to 1.488v when @ 3.8v causes me to crash though. even with the 100mv (allowing up to 1.5v) I run around 1.424-1.472v on average with the 1.488v spikes under loads.