I ordered a 3.4 478 Extreme but sadly the box turned up empty! (my first e8ay problem in over 110 transactions ) As it seems almost impossible to get a plain 3.4 northwood (let alone an Extreme) - I'm wondering about a Prescott. As previously mentioned, I'd love to reach 4GHz - will a 3.4GHz Prescott over-heat before it gets there? My water rig is working well - my 3.0 northwood is running 3.7GHz (1.6v) and the temp is 34 idle, 37.5 under load. - Toff.