I remember this happening for chips from the first step revision of Nehalem. When the demand for the i7 920 was way up, there were a bunch of better chips sold

I remember this happening for chips from the first step revision of Nehalem. When the demand for the i7 920 was way up, there were a bunch of better chips sold as such. Savvy overclockers knew which batch numbers they were and sought the particular runs.