Hades_au,

Thanks, after waiting a few days its looking like factoring and sieving are almost similar in speed. So as suggested I am doing factoring on 1 cpu and sieving on the other. My Xeons are straight up prp'ng. Should cover all of SOB.

BTW, do you run 4 instances of prp on your dual xeon boxes or run -o2 which is 3 instances on my xeon box HT enabled? Thanks.

e