20160204, 21:41  #12 
Jun 2012
101011110010_{2} Posts 
No it is not an especially slow time for my computer but definitely on the high side for a SNFS ~240. Lots of scatter in the ETA vs. SNFS curve though.
Your results show that performance in Linux is better than in Windows. I don't disagree, but I eventually left Linux as I got tired of arm wrestling my machines everytime I wanted to use them... 
20160224, 09:54  #13 
Mar 2013
7 Posts 
I am unable to reproduce the failure. Need more details on how to reproduce.
I tried Code:
D:\Factoring\lasieve4_ivybridge>gnfslasieve4I14e.exe v a f 24000000 c 2000 c189_147_41.txt gnfslasieve4I14e (with asm64): L1_BITS=15, SVN $Revision$ Warning: lowering FB_bound to 23999999. FBsize 1506969+0 (deg 6), 2888143+0 (deg 1) total yield: 3071, q=24002051 (0.09361 sec/rel) ETA 0h00m) 124 Special q, 762 reduction iterations reports: 34229068>499577>448037>350947>293902>293567 Number of relations with k rational and l algebraic primes for (k,l)=: Total yield: 3071 0/0 mpqs failures, 2240/2604 vain mpqs milliseconds total: Sieve 107431 Sched 0 medsched 41680 TD 19527 (Init 77, MPQS 2316) SieveChange 118852 TD side 0: init/small/medium/large/search: 2660 217 1398 3785 301 sieve: init/small/medium/large/search: 1248 15476 1039 35173 220 TD side 1: init/small/medium/large/search: 3041 393 1166 3743 383 sieve: init/small/medium/large/search: 1564 16673 942 32846 2250 Code:
n: 205451388964856467807686090421078666750691138189010020165236543387336128283211048921251478839880150378554118455189058228045898855699277369470472121604743428745579798048420314101101241961387 # 147^41+41^147, difficulty: 237.08, anorm: 6.37e+39, rnorm: 1.95e+45 # scaled difficulty: 237.08, suggest sieving algebraic side # size = 2.485e12, alpha = 0.188, combined = 2.415e13, rroots = 0 type: snfs size: 237 skew: 14.7100 c6: 1 c0: 10131387 Y1: 509111094534718962173411120845918138561 Y0: 1483273860320763 m: 44008401100288010210378427144625977757864842683924464711360809690583398911228987316128214321844953723667341332495287889981170421945600498539914605816457803581780075658984410989729763013655 alim: 48000000 rlim: 48000000 lpba: 31 lpbr: 31 mfba: 62 mfbr: 62 alambda: 2.5 rlambda: 2.5 
20160224, 14:42  #14 
Jun 2012
101011110010_{2} Posts 
Are you running on a Windows machine? The bug does not seem to occur in Linux.

20160224, 19:02  #15 
Basketry That Evening!
"Bunslow the Bold"
Jun 2011
40<A<43 89<O<88
3×29×83 Posts 
D:\Factoring\lasieve4_ivybridge>gnfslasieve4I14e.exe would certainly seem to indicate Windows

20160225, 00:38  #16 
"Serge"
Mar 2008
Phi(3,3^1118781+1)/3
5·1,811 Posts 
Unsure about the Windoze port, but the original sievers long ago in the past had the childhood disease of sieving quite poorly when some unwritten rules were violated by a poly. (And it did happen with the automatically generated xyyx polys because of the specificity of the construction.) These unwritten rules were:
1. Y1 > 0 2. Y1 <= Y0 These are easily accommodated for  one by negating the rat'nl poly, and the other, by flipping both polyns on their heads (i.e. swap all poly indices c_{j}, Y_{i} :: i,j for deg _{side}i). You may want to try that. EDIT: another, unrelated hunch to try in parallel. Because 147 happens to be 3*7^{2}, one can try to lower the skew by leaving 7^{4} out (that is do overmultiply the algebraic poly by 3 but not by 7^{2}; leave coeffs as 7^4*x^6 + 3*41^3*y^6, and m=x/y (or y/x as the case may be, I haven't pulled out a napkin to play; this, here, is the napkin ...and its margins are too narrow). Or 3^5*x^6 + 41^3*7^2*y^6 (less likely to be useful) Last fiddled with by Batalov on 20160225 at 00:50 
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