mersenneforum.org > EdH How I Run a Larger Factorization Using Msieve, gnfs and factmsieve.py on Several Ubuntu Machines
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 2019-08-19, 10:31 #2 aokle   Aug 2019 112 Posts I do not know about the max_coeff=9000, Help Me Hello EdH, "msieve -i comp94.n -s comp94.3 -nf comp94-3.fb -t 8 -np "poly_deadline=300 6001,9000"". The max_coeff can set any integer? "-t 8"=(NUM_CORES = 4)*(THREADS_PER_CORE = 2) ? when I calculate RSA 512bit, poly_deadline=300 is acceptable๏ผ Thank You.
2019-08-19, 13:34   #3
xilman
Bamboozled!

"๐บ๐๐ท๐ท๐ญ"
May 2003
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23×5×283 Posts

Quote:
 Originally Posted by EdH ... This thread will explain the steps I use to run msieve and gnfs on several computers which are already running Ubuntu and have msieve and the ggnfs package installed* and tested per: ...
Excellent!

I've been using factMsieve.pl et al. for years but haven't yet accumulated enough round tuits to automate it to the degree which you have achieved.

2019-08-19, 21:50   #4
EdH

"Ed Hall"
Dec 2009

13·347 Posts

Quote:
 Originally Posted by aokle Hello EdH, "msieve -i comp94.n -s comp94.3 -nf comp94-3.fb -t 8 -np "poly_deadline=300 6001,9000"". The max_coeff can set any integer? "-t 8"=(NUM_CORES = 4)*(THREADS_PER_CORE = 2) ? when I calculate RSA 512bit, poly_deadline=300 is acceptable๏ผ Thank You.
Hi aokle,

RSA-512 would mean a bit larger number than my example, so you would need to adjust your parameters accordingly. poly_deadline would most assuredly not achieve a good enough polynomial pair in 5 minutes for your number. I'm not sure I understand the other question, but you should adjust all the parameters based on how many machines will be used and what range you would like to use for your polynomial pair search.

Having said all the above, I've moved to using CADO-NFS across several machines and let it do "almost" all the parameter choice. All but the Linear Algebra phase will be run pretty much automatically across all machines. LA will be run on the server machine only. I have the setup for CADO-NFS in a similar thread to this one.

Ed

2019-08-19, 21:56   #5
EdH

"Ed Hall"
Dec 2009

13·347 Posts

Quote:
 Originally Posted by xilman Excellent! I've been using factMsieve.pl et al. for years but haven't yet accumulated enough round tuits to automate it to the degree which you have achieved.
Thanks xilman. I've never really played with the .pl version. I came on the scene when Brian was just about finalizing his .py code and got more familiar with it. Now I pretty much just use CADO-NFS, although I can factor a large composite quicker using a hybrid CADO-NFS/msieve script I occasionally play with.

 2019-08-20, 12:20 #6 aokle   Aug 2019 3 Posts Hi EdH, Think you for your help. I'm a little uncertainty: "poly_deadline=300 1,3000" "poly_deadline=300 3001,6000" "poly_deadline=300 6001,9000" when I excute "./msieve --help". some like that: poly_deadline=X stop searching after X seconds (0 means search forever) X,Y same as 'min_coeff=X max_coeff=Y' but I stil do not understand: the coeff range is 1-9000 ? max_coeff(9000) can be another integer at your case? Think you.
2019-08-20, 13:26   #7
EdH

"Ed Hall"
Dec 2009

13×347 Posts

Quote:
 Originally Posted by aokle Hi EdH, Think you for your help. I'm a little uncertainty: "poly_deadline=300 1,3000" "poly_deadline=300 3001,6000" "poly_deadline=300 6001,9000" when I excute "./msieve --help". some like that: poly_deadline=X stop searching after X seconds (0 means search forever) X,Y same as 'min_coeff=X max_coeff=Y' but I stil do not understand: the coeff range is 1-9000 ? max_coeff(9000) can be another integer at your case? Think you.
Hi aokle,

If you run an instance without the min/max_coeff, the coefficient value is chosen at random from 1 through the max_coeff that is chosen by msieve based on the composite. If you are running multiple machines there is a "slight" chance of more than one running the same coeff. To prevent this in my example, I set each machine to use a unique range. That way all the randoms of one are outside all the randoms of the others. As the composite gets larger, the max_coeff for the entire group of machines gets larger, but it is divided between all the machines using the min_coeff=,max_coeff==.

The poly_deadline chosen was just for the example size composite. With three machines searching, that was roughly equal to 15 minutes of searching across all three machines. In practice, I choose the total time I want to search and divide that by the number of machines I'll be using, similar to the max/min_coeffs.

Ed

2019-08-21, 02:26   #8
aokle

Aug 2019

316 Posts
Excellent!

Quote:
 Originally Posted by EdH Hi aokle, If you run an instance without the min/max_coeff, the coefficient value is chosen at random from 1 through the max_coeff that is chosen by msieve based on the composite. If you are running multiple machines there is a "slight" chance of more than one running the same coeff. To prevent this in my example, I set each machine to use a unique range. That way all the randoms of one are outside all the randoms of the others. As the composite gets larger, the max_coeff for the entire group of machines gets larger, but it is divided between all the machines using the min_coeff=,max_coeff==. The poly_deadline chosen was just for the example size composite. With three machines searching, that was roughly equal to 15 minutes of searching across all three machines. In practice, I choose the total time I want to search and divide that by the number of machines I'll be using, similar to the max/min_coeffs. Ed
Excellent!

2022-01-03, 20:43   #9
Yup

Jan 2022

18 Posts

Quote:
 Originally Posted by EdH (Note: I expect to keep the first post of each of these "How I..." threads up-to-date with the latest version. Please read the rest of each thread to see what may have led to the current set of instructions.) .... Factoring Large Composite Numbers
Hi Edh and everybody!
Please send link where I can get a factmsieve.py for factoring large numbers. Because this link doesn't work.

Last fiddled with by Uncwilly on 2022-01-04 at 00:41

2022-01-07, 16:31   #10
EdH

"Ed Hall"
Dec 2009

119F16 Posts

Quote:
 Originally Posted by Yup Hi Edh and everybody! Please send link where I can get a factmsieve.py for factoring large numbers. Because this link doesn't work.
Thanks for the note. The link has been updated.

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