Strange result with Prime95

[ShoeLace]

I tried to factor my range 7412000 -> 7413000 with prime95 just now


the worktodo.ini was created with the make_worktodo.pl with parameters


make_worktodo.pl 7412000 7413000 49 1.5

24 numbers with 7412000 <= n < 7413000
Searching for known factors in results.txt...
Removed 0 numbers using the factor file
24 numbers with 7412000 <= n < 7413000


i then ran this this with prime95 (widnows version i got from http://www.sslug.dk/~grove/sbfactor/)

and the only result i got was


10223*2^7412009+1 does not need P-1 factoring.
24737*2^7412071+1 does not need P-1 factoring.
24737*2^7412191+1 does not need P-1 factoring.
55459*2^7412194+1 does not need P-1 factoring.

etc..

and it was finished in like 1 min.

so i tried the sbfactor program and it found

605506658575261 | 28433*2^7412233+1

so for an expriemnt i tried
Pfactor=28433,2,7412233,1,52,9
and then it started doing something.


can i get some help/feedback on this?

[ceselb]

It looks like prime95 doesn't estimate correctly. It wasn't done with our numbers specifically in mind, so that's no huge surprise.

Have you input the correct factor depth? I haven't used prime95 myself, except for a short time while trialdividing at gimps a few years back.

[Mystwalker]

Correct me if I'm wrong, but AFAIK, the current version of SoBPM1 doesn't support floating point values as "the last value" (I've forgotten a suitable name).
Try it with a "2" instead, which means that a factor will save 2 PRP tests (first time check and double check). Maybe that does the trick...

[hc_grove]

Originally posted by ShoeLace



10223*2^7412009+1 does not need P-1 factoring.
24737*2^7412071+1 does not need P-1 factoring.
24737*2^7412191+1 does not need P-1 factoring.
55459*2^7412194+1 does not need P-1 factoring.

etc..

and it was finished in like 1 min.


Whenever I've experienced that, the reason has been that it was configured to use a max of 8MB of RAM, which just isn't enough.

I have no idea how to configure the windows version.

[ShoeLace]

excellent thank you.. i think it was the memory setting..


under Option->cpu there is a memory setting.. and it was defaulted to 8MB

ive set it to 512MB are recreated teh worktodo.ini with 49 and 2 and it seems to be working fine now.


NB: memory usage is saved in local.ini eg


OldCpuType=12
OldCpuSpeed=1795
CPUHours=24
DayMemory=768
NightMemory=768
DayStartTime=450
DayEndTime=141




thanks everyone

[ShoeLace]

last slightly dumb question..

where does prime95 output any factors that it finds?

are they in a format the teh submission page will accept etc..

???

[garo]

Prime95 puts all results in results.txt . This can be a problem since results.txt means something else for SOB. A work around is to insert his line in prime.ini

results.txt = factor.txt

where the results will now be stoerd in factor.txt

However the results are printed in a format that is different from what SoB expects. I wonder if anyone would write a script to convert the result format.

[Frodo42]

Originally posted by garo
However the results are printed in a format that is different from what SoB expects. I wonder if anyone would write a script to convert the result format.
I would love to have that script also.
It gets a bit tedious looking through al the tests done for factors, it was easier with the "old" fact.txt where factors had the correct format for submitting them


p|k*2^n+1

[hc_grove]

Originally posted by garo
However the results are printed in a format that is different from what SoB expects. I wonder if anyone would write a script to convert the result format.

I've been planning to write that script for a long time, now I did it:


#! /usr/bin/perl

use strict;
use warnings;

my $resultsfile = 'results.txt';

open(RESULTS,$resultsfile) or die "Couldn't open $resultsfile.\n";

open(FACT,'>fact.txt') or die "Couldn't open fact.txt.\n";

while (<RESULTS>) {
if (m/^(\d+)\*2\^(\d+)\+1 has a factor: (\d+)/) {
print FACT "$3 | $1*2^$2+1\n";
}
}
close(RESULTS);
close(FACT);

It assumes that the results are actually written to results.txt, but that can be changed in line 6 (counting the blanks).

[Frodo42]

thanks hc_grove :thumbs:
I guess had you in the back of my head when talking of that script and again you get the job done :bouncy:
btw. people should be careful if they have named their output file from prime95 fact.txt then line 10 should also be changed.