CPU PLL Voltage - [Auto, 1.50 ~ 3.00 in 0.02 steps] Selecting a higher PLL (phase lock-loop) voltage may help the installed CPU clock higher or may assist with maintaining stability when operating at higher FSB speeds. Most users will find they do not need to set this to anything above 1.50. Exercise caution when experimenting with higher values as there have been reported cases of CPUs losing cores after being subjected to voltages in excess of about 2.00V.
CPU VTT Voltage - [Auto, 1.20 ~ 2.46 in 0.02 steps] VTT is the termination voltage for data lines used to interface the MCH with the CPU die(s) via the Front Side Bus. Higher values can provide additional FSB overclocking margin, especially with 45nm dual-core processors and quad-cores CPUs in general. We have never found any additional gains to be had above 1.36 when using air- or water-cooling. Setting Auto should default to 1.10V for 45nm CPUs and 1.20V for 65nm CPUs. Knowing this, there appears to be a dead band between 1.10V and 1.20V where intermediate values cannot be selected - we are working with ASUS engineering to get this corrected.
