I currently have mine at 2.8GHz stably (using aftermarket cooler, but no water). It doesn't pass 55C when under load, and I'm still working on pushing it further. I have a different motherboard than you but it sounds like you have a pretty good one as well. I just set fsb to 244MHz, cpu multiplier at 11.5x, bump up the voltages a bit for the cpu (mine's at 1.325V) and NB (mine's at 1.35V.) You'll probably have to tweak the HT link frequency a bit to get it under 1800MHz, but the whole process shouldn't really be too tough if you have a decent cpu cooler.