IOH voltage add to 1.3V。1.4V for VTT/QPI。I tried this setting on Asus P6T-Deluxe and Gigabyte EX58-Extreme, mainly this two selections would help to gain a lot of FSB. For Gigabyte, i use VTT 1.6V since GA is always working better on high VTT.
Do you got any tricky setting to go that high?