Hello again friends and thanks for looking. I find myself here again seeking knowledge from the most wise. My question is... What is meant by a matching pair of CPU's?? I often see processors for sale as a matching pair. Secondly I am going to build a dual processor system(xeon dual 3.06's)do i have to uses a matching pair of CPU's? or can I buy one CPU from Mr x and another from Mr y? I thank you in anticipation of a response.