They all run on a 9x multiplier if I remember correctly, the difference is 0.1Ghz I think for each chip. i recommend the E2180, its a beast, On a cheap $20 Zalman cooler I got it stable at 3.4Ghz And its only cripple is the 1mb cache but that only makes a 7-10% difference, hell id take that for the 50-70% price difference