mersenneforum.org Very (large) PRPs?
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 2016-05-18, 15:52 #78 PawnProver44     "NOT A TROLL" Mar 2016 California 197 Posts 2.16 Gz processor is not that bad. Took 9.768 s. to find this prime, using the same methods I can use for larger PRPs. Now double each prp's digits 7 times, (4x times as much for doubled candidates) is about 1 day, 20 h. 27 min. Seems right? Last fiddled with by PawnProver44 on 2016-05-18 at 15:59
 2016-05-18, 15:58 #79 danaj   "Dana Jacobsen" Feb 2011 Bangkok, TH 32×101 Posts Joining the party for this random and otherwise uninteresting PRP: Code: time perl -Mntheory=:all -nE 'chomp; say length($_); say is_bpsw_prime($_); say is_frobenius_pseudoprime($_); say is_frobenius_khashin_pseudoprime($_); say is_frobenius_underwood_pseudoprime($_);' ~/Downloads/prp_6056.txt 6056 1 1 1 1 real 0m30.460s user 0m30.425s sys 0m0.012s So it passes BPSW (strong pseudoprime base 2 + extra strong Lucas), a Frobenius test, Khashin's Frobenius-type test, and Underwood's Frobenius-type test. The F-U test here uses GMP and takes less than 6 seconds. At 200k these should work fine, but Paul's gwnum version will be quite a bit faster. On my machine (X5550 2.67GHz), PFGW took 4x longer for a 2x larger input. ~95s at 50k digits, ~390s at 100k digits. No AVX. The time in the paragraph above is purely the time taken for a given composite candidate, and does not take into account how the expected number of tests until a PRP is found will go up as the size goes up. Last fiddled with by danaj on 2016-05-18 at 16:19  2016-05-18, 16:00 #80 paulunderwood Sep 2002 Database er0rr 2·3·691 Posts But does it have AVX? If you are running Linux on it you can type cat /proc/cpuinfo to see. Under windows you have go clickety click somewhere Last fiddled with by paulunderwood on 2016-05-18 at 16:12 2016-05-18, 16:06 #81 paulunderwood Sep 2002 Database er0rr 2×3×691 Posts Quote:  Originally Posted by PawnProver44 2.16 Gz processor is not that bad. Took 9.768 s. to find .... using the same methods I can use for larger PRPs. Now double each prp's digits 7 times, (4x times as much for doubled candidates) is about 1 day, 20 h. 27 min. Seems right? No! The primes will thin out as they get bigger. You need to multiply by 8 and extrapolating from 10 seconds is useless.  2016-05-18, 16:06 #82 PawnProver44 "NOT A TROLL" Mar 2016 California 197 Posts Command Window (thanks for command, is availible for up to 200k digits?): --------- C:\Users\Username\Documents> time perl -Mntheory=:all -nE 'chomp; say length($_); say is_bpsw_prime($_); say is_frobenius_pseudoprime($_); say is_frobenius_khashin_pseudoprime($_); say is_frobenius_underwood_pseudoprime($_);' ~/Downloads/prp_6056.txt The system cannot accept the time entered. Enter the new time: 440 The system cannot accept the time entered. Enter the new time: 16666 The system cannot accept the time entered. Enter the new time: ? --------- Just sticking to the sieve if that doesn't work.
 2016-05-18, 16:09 #83 paulunderwood     Sep 2002 Database er0rr 414610 Posts time is a Linux command to measure timing. Under windows it is used for setting the time!! Last fiddled with by paulunderwood on 2016-05-18 at 16:10
 2016-05-18, 16:14 #84 PawnProver44     "NOT A TROLL" Mar 2016 California 3058 Posts Sorry for all delay. I was too busy during this week and I haven't got a chance to download linux version of pfgw, pari/gp and more programs like primo and newpgen...
2016-05-18, 16:44   #85
Xyzzy

Aug 2002

22×32×5×47 Posts

Quote:
 Originally Posted by danaj It seems to try to open a file named 46, so I couldn't run it, but now I see it just writes one line at a time.
If you are bored and want to see the "program" in action, you can get a copy of that file here: http://www.mersenneforum.org/showthread.php?t=21252

Since there are 49 (so far) files to choose from, we probably should use a command line argument for the file name instead of hard coding it.

 2016-05-18, 17:50 #86 danaj   "Dana Jacobsen" Feb 2011 Bangkok, TH 16158 Posts For Windows you need to take into account how even today the DOS command shell is basically 1970's CP/M. Code: C:\>perl -Mntheory=:all -nE "chomp; say length($_); say is_bpsw_prime($_); say is_frobenius_pseudoprime($_); say is_frobenius_khashin_pseudoprime($_); say is_frobenius_underwood_pseudoprime(\$_);" prp_6056.txt You have to write your own little .bat script for timing if you want (use your favorite search engine). It should work on 200k inputs. I just ran it on a Windows laptop with the 50k digit PRP "10^49999 + 91701". It isn't fast -- ~2 hours for all four tests. Re Xyzzy's file, I was seeing those odd-looking forms on the PRPtop site when I tried the number above. Now I know where they came from!
 2016-05-18, 18:50 #87 PawnProver44     "NOT A TROLL" Mar 2016 California 197 Posts So here is what I will actually do: 1. Use Paul's pari/gp script for sieve and random number gen. + PFGW's prp test for all remaining candidates 2. Use Dana's perl/netheory script to preform stronger tests. 3. From calculations of 8x as much time for 2x the digits, would take 5.3333 days for my current aim. 4. I am thinking about seeing weather Dana's perl script hold 300k digits, 400k digits, etc. so I know what limits are placed. 5. Or use Xyzzy's Script (for sieving) 6. Laziest, but less efficient is pfgw's nextprime. If I get pfgw, pari/gp, etc...... set up by tomorrow, I will probably have 200k digit prp to show you soon.
 2016-05-18, 19:23 #88 Xyzzy     Aug 2002 22·32·5·47 Posts Do you have access to a Linux machine? If not, there are many free possibilities.

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