Thread: B1 and # curves for ECM View Single Post
 2012-08-21, 04:48 #1 Walter Nissen     Nov 2006 Terra 4E16 Posts B1 and # curves for ECM In the table in the readme , we find : Code: digits optimal B1 expected curves N(B1,B2,D) default poly 20 11e3 74 25 5e4 214 30 25e4 430 35 1e6 904 40 3e6 2350 45 11e6 4480 50 43e6 7553 55 11e7 17769 60 26e7 42017 65 85e7 69408 Table 1: optimal B1 and expected number of curves to find a factor of D digits with GMP-ECM. Why do the second derivatives change sign ? Does this come from the mathematics or is it from the details of the computer technology used to compute the estimates , such as available RAM , cache sizes at various levels , disk access times , etc. ?