I have a Duron 700 and I can only get to 950 with the multiplier and using 1.85 core voltage. if I use 3.5 on my I/O voltage instead of the 3.3 default it runs at 1000 fine. However; I need to know if raising my I/O voltage is safe. My temps are at about 41c even though I have an Alpha HS and Globalwin Fan.