20110718, 18:43  #34  
A Sunny Moo
Aug 2007
USA (GMT5)
3·2,083 Posts 
Quote:
The current state of the art sieving programs for these numbers are tpsieve and the srsieve family of sieves (srsieve, sr1sieve, sr2sieve, and sr5sieve, each being particularly applicable for different scenarios). tpsieve has been ported to CUDA (where a similar speedup over CPUs has been realized, akin to that with mfaktc for Mersenne numbers); it works most efficiently on very large continuous ranges of k and n, and as such it is most well suited to a large project. Currently, the PrimeGrid project is using this program through BOINC to sieve all of k<10000, n<6M on both the Riesel and Proth sides simultaneously; the sieve files produced by this effort are then made freely available to other projects (such as NPLB and RPS in the mersenneforum, and individual searchers coordinating in this subforum). With all the GPU power being thrown at this effort, everything below n=3M is at this point fully sieved to the optimal factor depth (the point at which CPUs can run primality tests faster than the GPUs can find factors); the current range in progress is for n=3M6M, with n=6M9M in the early initial stages of sieving. For some more specialized searches (for instance, such as those done by the Conjectures 'R Us project here at mersenneforum), tpsieve's preference for large swaths of k and n works against it; for these, one needs to use the srsieve programs, which unfortunately have not yet been ported to CUDA. I talked to the developer of tpsieve (Ken_g6 on this forum) about this, and he explained that srsieve's algorithm is much more difficult to implement on a GPU; he thus is not planning to undertake the effort in the near future. If anyone else, however, would like to try it, he would have the everlasting gratitude of the Conjectures 'R Us participants and others doing similar searches. Hopefully this explains things a bit! Max 

20110719, 00:22  #35 
Dec 2010
Monticello
3403_{8} Posts 
Terrible job...just terrible....*not!*
It does put a good bound on what to do with mfaktc, though...if I can ever get out from under work.... what wblipp had asked for was an mfaktcstyle TF on (41)^(large prime * various small, very smooth composites such as 2^3)1. It doesn't sound like it's worth it to extend to reisel or proth numbers. 
20110719, 13:02  #36 
"William"
May 2003
New Haven
941_{16} Posts 
I hope you are using 41 as a representative small number, not a hard coded constant. I'm interested in this for many small primes, not just 41. I'm worried that I have not accurately conveyed that idea.

20110803, 19:56  #37 
Mar 2006
Germany
2·5·293 Posts 
Updates:
 kvalues in page 8000<k<10000 are sorted  page for RPS Drive #7 completed (some missing countings still there) 
20110909, 11:23  #38 
Mar 2006
Germany
2·5·293 Posts 
New page for RPS Drive #11 inserted.

20111024, 16:27  #39 
Mar 2006
Germany
2·5·293 Posts 
I've included a page for the Project "TPS  Twin Prime Search" (under "Other Projects").
Data included (up to 20101019 so far):  primes found (with person, date)  number of candidates tested and primes found by user  distribution of primes (table and graph)  graph with pairs returned to LLRnet/PRPnet server per day  ranges overview Some data from that:  159 primes found  804016 candidates tested 
20111124, 00:46  #40 
Mar 2006
Germany
2·5·293 Posts 
I've included an ASCIIfile with Rieselprimes for 10000 < k < 100000 and
 all k's: n<=1007 (from G.Barnes)  k < 15000: n<=20000 (from T.Ritschel) Thanks both for the data. Some numbers:  the file is ~3MB in size  45000 kvalues  560708 primes  15280 twins The table gives for all kvalues the number of primes and the Nashweight, too. Twins are marked with '*'. 
20111226, 09:32  #41 
Mar 2006
Germany
2×5×293 Posts 
PrimeGrid found (by Timothy D. Winslow) the lagest Twin so far: 3756801695685*2^666669±1 on 20111225.

20111231, 23:19  #42 
Basketry That Evening!
"Bunslow the Bold"
Jun 2011
40<A<43 89<O<88
1C35_{16} Posts 
That's my last name. Who the hell is he?
Hmm. I found another Timothy Winslow online (and a whole family of Winslows. Presumably there are many of us.) Last fiddled with by Dubslow on 20111231 at 23:53 
20120203, 10:30  #43 
Mar 2006
Germany
2930_{10} Posts 
New Riesel Prime found by PrimeGrid:
162941*2^9937181 found by D.Domanov. This prime was overlooked by the RieselSieveproject. Now 56 candidates left. 
20120623, 17:48  #44 
Mar 2006
Germany
101101110010_{2} Posts 

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