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Old 2021-07-11, 19:02   #51
VBCurtis's Avatar
Feb 2005
Riverside, CA

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Originally Posted by bur View Post
And at roughly which digit length should I switch to c130 parameters? VBcurtis mentioned approximately every 30 bits I should switch +5 digits for the params, but at what starting points?
As you get into jobs that take days rather than hours, you'll want to test-sieve parameters yourself. There aren't solid rules-of-thumb for SNFS jobs like there are for GNFS, because optimal parameter choice depends in part on the size of coefficients in the poly.

That said, the formula given the post before yours allows you to plug in 130 for GNFS and solve for S; I get 180 or so. By the time you're at 200 digits, you ought to test params yourself or study the 14e queue submissions in NFS@home subforum to see what params were chosen for SNFS jobs of similar size. That research should keep you out of trouble of the "oops this job took twice as long as it should have" sense. When in doubt, use the bigger large-prime option.
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