JEDEC's standard testing does require DDR2 modules to withstand up to 2.3v, but that doesn't mean all DDR2 sticks are created equal. His RAM stick is rated at 1.8v, so pushing the voltage too much above its rated voltage would probably have diminishing returns. I have 4x1GB Corsair XMS sticks installed on my E6550 rig, and those are rated at 1.9v. Still rock-solid stable with 60MHz over its max supported speed for years. He's using a generic Hynix RAM stick and a Jetway motherboard; not much to work with. Also, it's a C2D, so the RAM speed is tied to the FSB; not much he can do there. At the mobo's default DIMM voltage of 1.95v, he couldn't even raise the FSB by 10MHz from stock clock. Now that he lowered it to 1.85v (the lowest possible on his mobo for some reason), he could raise the FSB to around 220MHz (from 200MHz).