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Old 2022-01-07, 13:57   #2
bsquared's Avatar
Feb 2007

7×11×47 Posts

Originally Posted by nivek000 View Post
Does the performance of SNFS vary wildly? I saw a C155 number (a factor of a larger C205 number) factor with SNFS in a little over 2 hours. Now I have a C160 running (a factor of a larger C213 number) that is estimated to run like 35 hours. The stated scaled difficulty is definitely different (167 for the former vs 218 for the latter). I am just surprised that there can be such a longer runtime for just 5 additional digits. Is this an effect of polynomial selection? Is it possible YAFU (version 2.07) made a poor choice for the latter number, or is this par for the course with SNFS?


- Kevin
Is the C160 a quartic, by chance? The degree of the polynomial matters and degree 4 for a C213 is suboptimal. Unfortunately this is the only way to make a SNFS poly, sometimes. It's better than running GNFS (although this isn't always true!).

If you like, post the target number and what yafu picked and we can help figure out if it was the best choice.

Last fiddled with by bsquared on 2022-01-07 at 13:59
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