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drummers-lowrise
1) Message boards : Aggie The Pew message board (Message 133434)
Posted 21 days ago by Scott BrownProject donor
It's actually quit asy to crat a sntnc without using th lttr "".


Hmmm who knew Michael was a Dr.

The sentence was clear as day, of course only for folks who normally read/write english.



My son said that I couldn't do it, but you know, my son is not always right about things!


2) Message boards : Aggie The Pew message board (Message 133226)
Posted 27 days ago by Scott BrownProject donor
Was able to bring back online some of the boxes that were being reconfigured about halfway through yesterday. Should keep me in the top 20, and maybe I can gain another spot or two.

3) Message boards : News : GFN-524288 Mega Prime! (Message 133209)
Posted 28 days ago by Scott BrownProject donor
On 18 September 2019, 11:52:32 UTC, PrimeGrid’s Generalized Fermat Prime Search found the Generalized Fermat mega prime:

2985036^524288+1

The prime is 3,394,739 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 3rd for Generalized Fermat primes and 28th overall.

The discovery was made by Peter Harvey (eXaPower) the United States using an NVIDIA GeForce GTX 1070 in an Intel(R) Core(TM) i5-4440S CPU @ 2.80GHz CPU with 8GB RAM, running Windows 8.1. This GPU took about 1 hour 49 minutes to probable prime (PRP) test with GeneferOCL3.

The PRP was verified on 19 September 2019, 22:56:55 UTC by Alexander Falk (Alexander Falk) using an NVIDIA GeForce GTX 970 in an Intel(R) Core(TM) i7-6700 CPU @ 3.40GHz with 16GB RAM, running Windows 10. This GPU took about 3 hours 17 minutes to probable prime (PRP) test with GeneferOCL5. Alexander is a member of The Knights Who Say Ni! Team.

The PRP was confirmed prime by an Intel(R) Core(TM) i7-7700K CPU @ 4.20GHz with 16GB RAM, running Windows 10 Professional. This computer took about 23 hours 48 minutes to complete the primality test using multithreaded LLR.

For more details, please see the official announcement.

4) Message boards : News : GFN-262144 Find! (Message 133208)
Posted 28 days ago by Scott BrownProject donor
On 9 September 2019, 18:15:29 UTC, PrimeGrid’s Generalized Fermat Prime Search found the Generalized Fermat mega prime:

8521794^262144+1

The prime is 1,816,798 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 13th for Generalized Fermat primes and 76th overall.

The discovery was made by Ken Ito (jpldcon4) of Japan using an NVIDIA GeForce GTX 980 Ti in an Intel(R) Xeon(R) CPU E5-2687W v3 @ 3.10GHz with 64GB RAM, running Microsoft Windows Server 2016. This GPU took about 27 minutes to probable prime (PRP) test with GeneferOCL2. Ken is a member of Team 2ch.

The prime was verified on 10 September 2019, 02:21:44 UTC by Brent Schneider (KWSN-SpongeBob SquarePants) of Nepal using an NVIDIA GeForce GTX 1080 in an Intel(R) Core(TM) i7-6700K CPU @ 4.00GHz with 16GB RAM, running Microsoft Windows 10 Enterprise. This GPU took about 28 minutes to probable prime (PRP) test with GeneferOCL2. Brent is a member of The Knights Who Say Ni! team.

The PRP was confirmed prime by an Intel(R) Xeon(R) E3-1240 v6 CPU @ 3.70GHz with 32 GB RAM, running Debian Linux. This computer took about 17 hours 30 minutes to complete the primality test using LLR.

For more details, please see the official announcement.

5) Message boards : Aggie The Pew message board (Message 132813)
Posted 39 days ago by Scott BrownProject donor
Yeah! I just made it to a 2nd shield!


Congratulations! Those 2080Ti cards hard at work I think!

6) Message boards : Fermat Divisor Search : Fermat Divisor Search (Message 132786)
Posted 41 days ago by Scott BrownProject donor
At what point would it be best to switch to multithreading? Once they surpass the size of PPS-MEGA maybe?


Right now, here are my suggestions...

pre-AVX Intel including Xeon (e.g., i7-950) -- You should already be running -t4

Older AMD (e.g., FX-8350) -- Max it out or come close. I am running -t6 because I have two GPUs in the only one of these I am running at the moment

most Sandy-Bridge through Haswell (consumer CPUs) -- -t2 for now, but switching to -t4 at PPS Mega levels

post-Haswell (consumer CPUs) -- -t1 for now going to -t2 at PPS Mega levels (and maybe -t3 shortly after that for the six core boxes, etc.)

Xeon with AVX or later, multi-CPU machines, Pro-sumer series CPUs (like the Haswell EP 6-core, etc.) -- Test, Test, Test! Too much variation here to give advice even within the same CPU family.

7) Message boards : Fermat Divisor Search : Fermat Divisor Search (Message 132647)
Posted 45 days ago by Scott BrownProject donor
When we come to the small k, here is the "table" we try to extend:

3: 41, 209, 157169, 213321, 303093, 382449, 2145353, 2478785
5: 7, 25, 39, 75, 127, 1947, 3313, 23473, 125413
7: 14, 120, 290, 320, 95330, 2167800
9: 67, 9431, 461081, 2543551
11: 18759, 960901
13: 20, 114296
15: 229
17: 147, 747, 6539
19: 6838, 9450, 23290
21: 41, 276, 94801
23:
25: 2141884
27: 455, 672007
29: 57, 231, 2027, 4727
31:
33: 18766
35:
37: 16
39: 13, 113549
41:
43:
45:
47:
49:

Each row is of the form:

k: (all known n that make k*2^n+1 a Fermat divisors)

/JeppeSN



I am kind of partial to k=9, but I might be a little biased. ;)


8) Message boards : Number crunching : Badges III (Message 132445)
Posted 55 days ago by Scott BrownProject donor

I found no AP25 in my 100+ million, but that may be deceiving since the badge and credit totals also include the old AP26 search. I am not sure the odds of finding an AP25 in the old search and the current search are the same.

9) Message boards : Generalized Fermat Prime Search : Radeon VII numbers (Message 132394)
Posted 56 days ago by Scott BrownProject donor

So if you have a functioning GTX 580 that's still sucking electrons out of the wall socket, it will use double precision on GFN-21 and GFN-22. Anything newer probably won't.


There are also some post-Fermi Titan, Quadro, and Tesla cards that might select the double-precision transform.

10) Message boards : Number crunching : Better multi-threading (Message 132393)
Posted 56 days ago by Scott BrownProject donor
Just to clarify this a bit for myself. Let's say I am using a common i7 CPU with 4-cores and 8-threads. HT is turned on, but I want to run LLR only at 50%. I would set the following:

MAX-JOBS: 4
MAX-CPUs: 1


That would be the -t4 equivalent. Is that correct? And this will have no effect on the GPUs that are also running non-LLR PG tasks in the system.


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