mersenneforum.org  

Go Back   mersenneforum.org > Extra Stuff > Miscellaneous Math

Reply
 
Thread Tools
Old 2020-04-21, 12:35   #78
kriesel
 
kriesel's Avatar
 
"TF79LL86GIMPS96gpu17"
Mar 2017
US midwest

23×32×59 Posts
Default

Quote:
Originally Posted by kriesel View Post
80-81 under way.
Done. Typical of the 8 processes is
Code:
M(60651732991) has 0 factors in range k = [9966119042880, 19932270758400], passes 14-15
Performed 47147307808 trial divides
Clocks = 05:46:53.712
mfactor-base-2w -m 60651732991 -bmin 80 -bmax 81 -passmin 14 -passmax 15 done at Tue 04/21/2020  7:23:50.14
kriesel is online now   Reply With Quote
Old 2020-04-23, 00:20   #79
paulunderwood
 
paulunderwood's Avatar
 
Sep 2002
Database er0rr

32×7×53 Posts
Default

Thanks kriesel. Now we have to wait for some revolutionary hardware to do the PRP/LL test of M(60651732991)
paulunderwood is offline   Reply With Quote
Old 2020-05-12, 05:35   #80
paulunderwood
 
paulunderwood's Avatar
 
Sep 2002
Database er0rr

32·7·53 Posts
Default Another idea

Code:
{forprime(p=3,30000000000,if(
Mod(Mod(1,p+17)*x+2,x^2-3)^lift(Mod(2,p+1)^p)==1&&
Mod(Mod(1,p+257)*x+2,x^2-3)^lift(Mod(2,p+1)^p)==1&&
Mod(Mod(1,p+65537)*x+2,x^2-3)^lift(Mod(2,p+1)^p)==1,
print([p,factor(p+1)])))}
[3, Mat([2, 2])][2147483647, Mat([2, 31])]
[7, Mat([2, 3])]
[31, Mat([2, 5])]
[127, Mat([2, 7])]
[4423, [2, 3; 7, 1; 79, 1]]
[8191, Mat([2, 13])]
[131071, Mat([2, 17])]
[524287, Mat([2, 19])]
[2147483647, Mat([2, 31])]
Produces only one non-2^p-1 Mersenne exponent. The following produces two:

Code:
{forprime(p=3,30000000000,if(
Mod(Mod(1,p+17)*x+2,x^2-3)^lift(Mod(2,p+1)^p)==1&&
Mod(Mod(1,p+65)*x+2,x^2-3)^lift(Mod(2,p+1)^p)==1&&
Mod(Mod(1,p+65537)*x+2,x^2-3)^lift(Mod(2,p+1)^p)==1,
print([p,factor(p+1)])))}
[3, Mat([2, 2])]
[7, Mat([2, 3])]
[31, Mat([2, 5])]
[127, Mat([2, 7])]
[607, [2, 5; 19, 1]]
[4423, [2, 3; 7, 1; 79, 1]]
[8191, Mat([2, 13])]
[131071, Mat([2, 17])]
[524287, Mat([2, 19])]
[2147483647, Mat([2, 31])]

Last fiddled with by paulunderwood on 2020-05-12 at 05:44
paulunderwood is offline   Reply With Quote
Old 2020-07-25, 13:11   #81
kriesel
 
kriesel's Avatar
 
"TF79LL86GIMPS96gpu17"
Mar 2017
US midwest

424810 Posts
Default

M60651732991 has been run with no factor found through 85 bits TF using Ernst Mayer's Mfactor program.
Sixteen processes running a pass each on dual-E5-2690 gave the following range of run times (less than 3 days, ~0.97% range max-min). Impact on prime95 progress using all physical cores is about a 10% slowdown during that time. Apparently hyperthreading is pretty effective for Mfactor runs. I estimate from a large extrapolation of https://www.mersenneforum.org/showpo...7&postcount=12 that the TF optimal stopping point for this exponent on cpu is around 95 bits. An estimated bit level duration is 2(95-85) times 67.5 hours = 7.9 years for the last bit level, 15.8 years cumulative, well out of reach. The odds of finding a factor in those 10 bit levels are around 11%. A 64-bit mfaktc version on a modern gpu would be good for accelerating this, but none exists. (Estimated gpu TF limit 99 bits, ~15% odds of factor with an NVIDIA RTX 2080 Super.)
Code:
M(60651732991) has 0 factors in range k = [159458035376640, 318916087089600], passes 14-14
Performed 377347101769 trial divides
Clocks = 67:47:56.301
mfactor-base-2w -m 60651732991 -bmin 84 -bmax 85 -passmin 14 -passmax 14 done at Sat 07/25/2020  4:05:44.19 

M(60651732991) has 0 factors in range k = [159458035376640, 318916087089600], passes 9-9
Performed 377346866607 trial divides
Clocks = 67:08:56.768
mfactor-base-2w -m 60651732991 -bmin 84 -bmax 85 -passmin 9 -passmax 9 done at Sat 07/25/2020  3:26:40.17

Last fiddled with by kriesel on 2020-07-25 at 14:02
kriesel is online now   Reply With Quote
Old 2020-07-25, 16:03   #82
kriesel
 
kriesel's Avatar
 
"TF79LL86GIMPS96gpu17"
Mar 2017
US midwest

23×32×59 Posts
Default

Quote:
Originally Posted by kriesel View Post
on dual-E5-2690
actually dual Xeon E5-2697v2, which are 12-core +HT each. So one could do TF n bits to n+1 on 8 cores, and n+1 to n+2 on 16 cores, simultaneously, and still leave considerable capacity for prime95.
kriesel is online now   Reply With Quote
Reply

Thread Tools


Similar Threads
Thread Thread Starter Forum Replies Last Post
The "one billion minus 999,994,000" digits prime number a1call Miscellaneous Math 179 2015-11-12 14:59
question range 1 billion to 2 billion? Unregistered Information & Answers 7 2010-08-12 06:25
Billion digit prime? lfm Operation Billion Digits 6 2009-01-07 01:17
Factoring a 617-digit number? Shakaru Factoring 2 2005-02-23 19:22
10,000,000 digit number Unregistered Software 3 2004-03-03 19:20

All times are UTC. The time now is 15:11.

Sat Aug 15 15:11:25 UTC 2020 up 2 days, 11:46, 0 users, load averages: 1.65, 1.86, 1.88

Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2020, Jelsoft Enterprises Ltd.

This forum has received and complied with 0 (zero) government requests for information.

Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.2 or any later version published by the Free Software Foundation.
A copy of the license is included in the FAQ.