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Old 2011-11-04, 20:23   #8
schickel's Avatar
"Frank <^>"
Dec 2004
CDP Janesville

2·1,061 Posts

Originally Posted by Andi47 View Post
I am not sure whether LaurV can finish this one as an one-man job.

One of my biggest "one man" factorization so far was a c153 cofactor of 2,1766M, and I used a similar computer for it (core 2, 2 gigs RAM).

After finishing sieving I attempted to do the matrix, and what happened then, can be seen in that thread beginning from post #157: Matrix generation failed with a "failed to reallocate 1.63 GB" error. On a 32 bit windows system it was not possible to do this linalg job, not even when I moved to a P4 with 3 Gigs RAM (also with 32-bit windows), because 32-bit windows is not able to handle the adress space which is needed for this matrix. When I switched to linux, it happily worked out.

So if LaurV's computer is running on a 64 bit system and with a 64-bit binary of msieve, 156 digit GNFS should be possible (but close to the edge of available RAM).
For 32-bit systems it could end up in a balancing act between extreme oversiving for squeezing the matrix in smaller amount of RAM an failing when it's way too oversieved and runs out of cliques in the filtering step.
Ugh....hadn't even considered that.

Well, if it comes to that, there are several people that could do the post-processing on the job.
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