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2021-09-12, 11:18   #382
kriesel

"TF79LL86GIMPS96gpu17"
Mar 2017
US midwest

33×5×43 Posts
MM127 is on its last mmff kernel & 3 bits

Quote:
 Originally Posted by Prime95 Today I'm releasing a beta version of a GPU factoring program for the double-Mersennes (MM61, MM89, MM107, MM127) and small Fermat numbers (F26 to F157). Sources attached. Nvidia cards with 2.0 compute capability is required.
Quote:
 Originally Posted by Uncwilly I would love for this to be the end of the "MM127 is prime" speculation!
Quote:
 Originally Posted by Gary With these changes, all 43 known factors within the range of mmff can be verified ... Here is source with these changes and a CUDA 10.1 Linux binary that will hopefully run on Kepler or later (--gpu-architecture=compute_30). I included Serge's patch to print factors found in K*2^N+1 form. If you want factors in the old format, use output.c from the 0.28 release. I also fixed a few other misc things, and changed the version to 0.28.1 to identify this binary. I am not sure who the current owner of mmff is, but if I changed anything in a "bad" way please feel free to fix it and re-post.
If I read the v0.28 source correctly, TF on MM127 is supported up to factors 2188. MM127 has been trial factored to slightly over 2185. A rough estimate of time to complete TF up to the limit of v0.28 is 5 RTX2080-years. That limit could be reached within 2 years by application of multiple GPUs on different blocks in parallel.

2185 / 2 /(2127-1) is ~257 which is 144,115,188,075,855,872: going to 288.23E15 (186 bits) would be roughly 6 x 144.12 = 865 days = 2.37 years on a single GTX1650.
To go to 187, 4.74 years more; to 188, 9.5 years more; total 14.24 GTX1650-years, or about 5 RTX2080-years.
Four GTX1650 plus 2 RTX2080 could get there in ~1.5 years, if no factor is found before then. (I estimate factor odds from 185 through 188 as 1.6%.)

Other supported double mersennes have a little more bits margin remaining in mmff v0.28.
Code:
MMp        URL                                  k max done   ~bits   kernels’ max bits    bits left
MM31   http://www.doublemersennes.org/mm31.php    450.E15    90.64    89, 96                5.36
MM61   http://www.doublemersennes.org/mm61.php    230.E15   119.67    108, 120, 128         8.33
MM89   http://www.doublemersennes.org/mm89.php     54.E15   145.58    128, 140, 152, 160   14.42
MM107  http://www.doublemersennes.org/mm107.php    10.E15   161.15    152, 160, 172        10.85
MM127  http://www.doublemersennes.org/mm127.php   145.E15   185.01    183, 185, 188         2.99
Of these, MM31 has known factors.

Last fiddled with by kriesel on 2021-09-12 at 11:20