20090204, 11:01  #1 
(loop (#_fork))
Feb 2006
Cambridge, England
7×911 Posts 
109!+1 polynomial search
Let's do the fourthbiggest public GNFS job yet.
EM43 is a bit bigger, but I want to reserve that for running with msieve's new polynomial selection once the parameterisation is sorted out. Pick a number between zero and 1000 which hasn't been picked before, and post saying which you've picked; as far as I know, you're no more likely to find a good polynomial in any range than in any other. I will use '389' as the example number. Put the line Code:
N 144385958320249358220488210246279753379312820313396029159834075622223337844983482099636001195615259277084033387619818092804737714758384244334160217374720000000000000000000000001 Obtain (from http://www.mersenneforum.org/showpos...10&postcount=2, or by building them yourself from ggnfs svn) the pol51m0b and pol51opt executables. Run Code:
pol51m0b b bang109.389 p 8 n 2e26 a 38900000 A 39000000 which will take about 14 hours on one core2/2400 core (NB it's much quicker for smaller ranges, only about three hours for range 000) and produce a file bang109.389.51.m with between a few hundred and a few thousand lines. Run Code:
pol51opt n 1e26 N 2e23 b bang109.389 e 7.0e14 Code:
BEGIN POLY #skewness 595776.02 norm 2.01e+25 alpha 6.38 Murphy_E 8.73e14 X5 38911605600 X4 108887534254406738 X3 169136961931062772632541 X2 25334292654996602951023137471 X1 15547530941799324358915720760520733 X0 1511957996366190506345629253321928760525 Y1 25670792597862397667 Y0 1299837812369852195092370228249064 M 50224823982718742995802804137379401708408180831986072195588571703671977210660885216197454152428679820859446461925150563600872030292505341428504963761763233931421015774088825570 END POLY If there are any lines beginning 'BEGIN POLY' in bang109.389.cand with a Murphy_E value greater than or equal to 1.00e13 (your favourite platform's equivalent to Code:
grep urph bang109.389.cand  sort g k 10  tail Repeat the whole process until March 1st or until you're fed up. I suspect there's a polynomial with a score better than 1.1e13 to be found, and every 0.01e14 improvement in the score will save us several dozen CPUhours at the sieving stage; we'll start sieving with the best polynomial that's been found by March 1st Reservations closed 18 February; we have 1.1e13 polynomials coming out of our ears Reservations fivemack 000009 mdettweiler 010 batalov 011 Jeff Gilchrist 012019 batalov 020029 Jeff Gilchrist 030032 smh 033035 Jeff Gilchrist 036039 amphoria 040042 mdettweiler 043 batalov 044046 andi47 047 batalov 048049 sean 050 Jeff Gilchrist 051059 smh 060069 amphoria 070074 smh 075079 Andi_HB 080081 sean 082087 andi47 088 batalov 090099 bsquared 100110 bsquared 113200 amphoria 201206 sean 207218 amphoria 224232 smh 250254 Jeff Gilchrist 270299 fivemack 300399 except 333, 334 Jeff Gilchrist 400409 Jeff Gilchrist 500529 Jeff Gilchrist 530549 Xyzzy 111, 112, 222, 223, 333, 334, 444, 445, 555, 556, 666, 667, 777, 778, 888 and 889. JoeO 9991000 Blocks done fivemack 000009 mdettweiler 010 batalov 011 Jeff Gilchrist 012019 batalov 020029 Jeff Gilchrist 030032 smh 033035 Jeff Gilchrist 036039 amphoria 040042 mdettweiler 043 batalov 044046 batalov 048049 sean 050 Jeff Gilchrist 051059 smh 6069 amphoria 7074 smh 7579 Andi_HB 080081 sean 082087 batalov 090092 amphoria 201206 sean 207212 amphoria 224229 smh 250254 Jeff Gilchrist 290299 fivemack 365399 Jeff Gilchrist 400409 Jeff Gilchrist 500529 Incremental records Code:
3/2 fivemack 8.56 77918820 4/2 fivemack 8.73 38911605600 5/2 batalov 9.01 2207281680 5/2 fivemack 9.03 38980754880 5/2 batalov 9.39 2050946160 5/2 Jeff Gilchrist 9.51 1955460000 5/2 smh 9.54 3320126820 6/2 batalov 10.6 2601876960 9/2 Jeff Gilchrist 11.3 50353706160 13/2 amphoria 11.5 22748948520 Last fiddled with by fivemack on 20090218 at 10:12 Reason: accumulate many reservations 
20090204, 11:08  #2 
Oct 2004
Austria
2·17·73 Posts 
reserving 47 (look at my nick. )
Last fiddled with by Andi47 on 20090204 at 11:10 
20090204, 12:48  #3 
Nov 2008
2322_{10} Posts 
How much RAM will this (the poly search) need?

20090204, 13:15  #4 
Oct 2004
Austria
2·17·73 Posts 

20090204, 15:07  #5 
A Sunny Moo
Aug 2007
USA (GMT5)
6249_{10} Posts 
I'll do 010.

20090204, 15:09  #6 
Tribal Bullet
Oct 2004
2×3×19×31 Posts 
I'll get msieve v1.40 out as soon as fivemack gives me some parameters for such large jobs; the new poly selection should be run with a leading coefficient perhaps 10100x smaller than what is being given to pol5. I can also run one or two machines locally with my local sources hacked to allow a monstersize input like this.

20090204, 18:16  #7 
Nov 2008
4422_{8} Posts 
I'll take 011 (beware, I will be out quite a bit over the next few days and I have an aliquot sequence, so I may not have my results in for a while).

20090204, 19:14  #8 
Aug 2004
New Zealand
13×17 Posts 
I will do 050. Should have more resources for this from next week.

20090204, 19:25  #9 
Nov 2008
2×3^{3}×43 Posts 
I'm doing my work in 10 sections, doing pol51opt at the end of each one, so I get an idea of what sort of polys I'm getting. Also, I don't want to have to spend too much time at the end doing pol51opt, so I can turn the computer off and save energy.

20090205, 01:39  #10 
A Sunny Moo
Aug 2007
USA (GMT5)
3·2,083 Posts 
My computer just got rebooted due to a power flicker in the middle of the pol51opt stage of my range. Is there anything I can do to recover the alreadycompleted work? It had been running the pol51opt stage for at least a couple of hours.

20090205, 03:15  #11 
"Serge"
Mar 2008
Phi(4,2^7658614+1)/2
47×197 Posts 
Yes, there's a manual recovery 
http://www.mersenneforum.org/showpos...2&postcount=26 If you didn't redirect the output from the pol51opt then you have to check the last found X5/Y1 values from the .cand file. I use a script like this one: Code:
#!/bin/csh set i=25 set j=`/bin/echo $i 1 + p dc` cp p P109.389.data P109.0$i.data nohup nice ./pol51m0b b P109.0$i p 8 n 2e26 a ${i}00000 A ${j}00000 nohup nice ./pol51opt n 1e26 N 2e23 b P109.0$i e 7.0e14 > P109.0$i.out & 
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