Quote:
Originally Posted by xilman
I've seen it, and discussed it with Peter Montgomery. We never came to any firm conclusions, other than that the matrix should not be too oversquare (very unlikely in your case, given your experience, though I mention it for the possible edification of other readers) and that sometimes there are too many duplicated rows in the matrix. Peter modified the code to look for the latter. A few are normal  usually corresponding to factorbase primes which are factors of the full SNFS number.
The only practical solution we ever found was to refilter and produce a slightly different matrix. I will be slightly surprised if subsequent runs produce a different and more useful answer. If it does, it may be an indication that the initial random vectors chosen at the start of the algorithm turned out not to be useful. I don't remember whether I've ever seen that happen in practice.
Paul

The matrix has 3392K rows and 3395K columns.. Very nearly square.
The same matrix is now running on a different machine. It will finish
Saturday.