With good cooling and a good motherboard with AGP/PCI lock and voltage boost, expect 2GHz +/- a few. Stock cooling with no voltage boost and no AGP/PCI lock, expect 1.8-1.9GHz. I had a similar setup, a 1.6 Willy on a Shuttle motherboard using the VIA P4X266 chipset. I was able to run mine at around 1750 stable. Would POST at around 1900 and would get into Windows at over 1800, but it really only tolerated that minor bump. May have been due to no AGP/PCI lock, however, because the board didn't have voltage boosts and even undervolted the CPU and I ran the stock cooler with nice and low temperatures.