Quote:
Originally Posted by wreck
I've found the lpba is 32 from NFS@Home's website,so it is not oversieved. What surprised me is that this number was factored with lpba 32,is there any suitable reason to not use lpba=31?

Well, 250M raw relations were sufficient, while 313M were obtained. On what basis do you call it not oversieved? Or is 25% extra relations pretty standard for NFS@home projects to make the matrices easier?
I believe for GNFS, mid 160s is where 31 and 32 bits takes the same time to sieve. At C170, the larger matrix that 32 might produce should be made up in sievetime savings. See
http://mersenneforum.org/showpost.ph...postcount=1732 for reference about C164 taking no more time to sieve with 32 bit than C163 took with 31bit.