I bought it an Intel 3.0 Ghz retail box CPU from Fry's. The guy there couldn't tell me whether it was an E or a C and I am not savvy enough to know. Can someone tell me how to figure it out? Second of all, if it is a C, are all 3.0 Northwoods created equal? i.e. are they all made the same way with the same features, etc?