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-   -   Reserved for MF - Sequence 3408 (https://www.mersenneforum.org/showthread.php?t=18421)

VBCurtis 2015-11-01 18:11

168 hr later, I have factors! Second dependency, else it would have completed under 7 days; as it is, I needed the help from Daylight Savings to make it under 7 days. :)

Some stats:
143.4M raw relations w/31-bit LP, 123.4M unique
147 hr sieving on 6 HT cores (900 CPU-hr, or 1800 thread-hr)
5.9M matrix at target density 90, 20 hr to solve on 6 threads (linux doesn't manage HT well- some cores were idle during this time; I will experiment with more threads to see if lower idle-core-time makes up for the thread contention)

The sequence rises through i1595; a c164 is in the middle of a t40 presently. I'll update factordb later today.

VBCurtis 2015-11-02 06:35

i1591 through 1594 are added to factordb. 1595 is listed as c175, but aliqueit/ecm is currently working on a c164 (I think that since I invoked aliqueit to update the sequence to factorDB while another copy was still running, it didn't report the trivial prime found).

The c164 has had over half a t45, with the second half finishing overnight. Any public efforts (Sean?) should begin at t50 level.

The sequence has grown to 189 digits.

swellman 2015-11-02 12:51

Ok I'll start ECM at t50 on the C164 later today. How much ECM do you want before starting GNFS?

fivemack 2015-11-02 14:16

[QUOTE=VBCurtis;414507]5.9M matrix at target density 90, 20 hr to solve on 6 threads (linux doesn't manage HT well- some cores were idle during this time; I will experiment with more threads to see if lower idle-core-time makes up for the thread contention)[/QUOTE]

I get round the Linux scheduling problem with 'taskset -c 0-5 msieve ... ... -t 6' to lock it to running on one thread per core

Xyzzy 2015-11-02 14:48

[QUOTE=fivemack;414637]I get round the Linux scheduling problem with 'taskset -c 0-5 msieve ... ... -t 6' to lock it to running on one thread per core[/QUOTE]We just recently started doing this at fivemack's suggestion and it works wonderfully!

:tu:

We actually modify the process after it starts, but that accomplishes the same thing and uses the same 'taskset' program.

[FONT=Courier New] taskset -p -c [I]x y[/I][/FONT]

where [I]x[/I] is the core number and [I]y[/I] is the process id.

VBCurtis 2015-11-02 17:00

Thanks for the protip!! I still use the python script; can I call taskset from the script by adding the command ahead of factmsieve's invocation of msieve {...} -nc2?

VBCurtis 2015-11-02 17:05

[QUOTE=swellman;414630]Ok I'll start ECM at t50 on the C164 later today. How much ECM do you want before starting GNFS?[/QUOTE]

I use 0.31 * digits for GNFS, which gives me about 1.5t50 here. A C164 is a nontrivial factorization, but one I'd be likely to try in December if it is deemed too small for NFS @ Home and nobody else picks it up.

The t45 finished overnight.

swellman 2015-11-02 17:45

I should finish a single t50 in a few days, and willing to run it up to 5000 curves at t55 level as well. Beyond that it belongs to GNFS.

Xyzzy 2015-11-03 02:20

[QUOTE=VBCurtis;414657]Thanks for the protip!! I still use the python script; can I call taskset from the script by adding the command ahead of factmsieve's invocation of msieve {...} -nc2?[/QUOTE]Yep!

[url]https://www.google.com/search?q=site%3Amersenneforum.org+taskset+msieve[/url]

swellman 2015-11-05 16:16

The C164 completed t50 with no hits. Running another 5k curves @B1=110M. Should be done by Sunday.

swellman 2015-11-08 10:27

5000 curves completed @B1=110M, with no hits. Releasing the C164.


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