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Old 2013-10-12, 14:24   #1
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"Ed Hall"
Dec 2009
Adirondack Mtns

23·3·5·31 Posts
Default Poly Search vs Sieving times

Sorry for the neophyte question, but for smaller composites ~150 digits across multiple machines, is there a real gain in overall sieving if a poly with a greater than expected E score is found early in the search?

Msieve v. 1.52 (SVN 886)
random seeds: 55df12b7 e5d3c816
factoring 218876969782929216599190531580538390484044829345681891460187089862281796240529496476113446316632558113449224677358919720113328517497603198421529 (144 digits)
searching for 15-digit factors
commencing number field sieve (144-digit input)
commencing number field sieve polynomial selection
polynomial degree: 5
max stage 1 norm: 8.34e+21
max stage 2 norm: 1.39e+20
min E-value: 1.03e-11
poly select deadline: 311905
time limit set to 86.64 CPU-hours
expecting poly E from 1.12e-11 to > 1.29e-11
(The msieve machine has four cores and I hard set the search time to 12 hours.)

The following poly was found within the first few minutes:
# norm 8.158791e-14 alpha -8.748871 e 1.309e-11 rroots 5
skew: 52981938.39
c0: 5925697648913135366967245004294844179177
c1: 468536815244189902014756820336233
c2: -26076232373209850831435621
c3: -542019174557361769
c4: 10239243052
c5: 48
Y0: -21467961164039091417408999106
Y1: 1118175346469539
I'm running several machines and expect the sieving and LA to take approximately four days. (Of course, I may be way off.)

Would a better poly outweigh the 11 hours of search time left for a 48-60 hour project?


Last fiddled with by EdH on 2013-10-12 at 14:26 Reason: added info
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