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drummers-lowrise
1) Message boards : Storm message board (Message 127761)
Posted 46 days ago by Profile MyrskylyhtyProject donor
When in doubt, use the SI-units:

2 gigacredits

Congrats!
2) Message boards : Storm message board (Message 126649)
Posted 69 days ago by Profile MyrskylyhtyProject donor
do you know how Jean program works?

would be useful for some primes that I have

I'm talking about this:
http://jpenne.free.fr/index2.html

this is a LLR primlality test, and I don't know how it works


It is quite similar test to Lucas-Lehmer test. Numberphile has a nice video on it: https://www.youtube.com/watch?v=lEvXcTYqtKU (See also here: https://en.wikipedia.org/wiki/Lucas%E2%80%93Lehmer_primality_test)

To upgrade it into Lucas-Lehmer-Riesel test, some info is here https://en.wikipedia.org/wiki/Lucas%E2%80%93Lehmer%E2%80%93Riesel_test

Most likely the LLR program itself has a lot of optimizations, e.g. using FFT to multiply.
3) Message boards : Proth Prime Search : Where are PPS mega k=15 to 99? (Message 126563)
Posted 71 days ago by Profile MyrskylyhtyProject donor
PPS Mega started on PRPNet, that's where those low-k candidates were tested. We never felt any great need to DC them. PPS Mega was then n=3.322M-3.6M.

k=3 is tested in 321
k=5 and k=7 were tested to n=6M years ago (I have no idea why)
k=9 was tested to n=4M years ago.
k=11-99 will start again at n=3.6M

The next PPS Mega candidate file to be loaded starts at n=3.6M so we'll soon have data on the stats page for those k's. I'm sure we'll be loading that during TdP.


Thanks for the info! I also talked about k=15-99 in my thread Status and strategy for small k values, and now these k appear on the Stats Mega LLR page! Will they start from n=3.32M? /JeppeSN


From your linked thread: "k=11-1199 will start being tested in MEGA at n=3.6M+ the next time we need to load work there"
4) Message boards : Proth Prime Search : Where are PPS mega k=15 to 99? (Message 126509)
Posted 72 days ago by Profile MyrskylyhtyProject donor
Here's some benchmarks on FFT size = 200K on the i7-7700K (k=11, n=3600003):

4 tasks, -t1, 0.69 ms per bit /4 = 0.1725 ms per bit "overall"
2 tasks, -t2, 0.48 ms per bit /2 = 0.24 ms per bit "overall"
1 task, -t4, 0.28 ms per bit

For comparison, with FFT = 256K, k=1199, n=3600003

4 tasks, -t1, 0.85 ms per bit / 4 = 0.2125 ms per bit "overall"
2 tasks, -t2, 0.43 ms per bit = 0.215 ms per bit "overall"
1 task, -t4, 0.233 ms per bit

Interestingly, the lower FFT size is much slower with multithreading, which really feels counter-intuitive. So keep this in mind when selecting multithreading for your machine. I'm definately going with -t1 on the i7-7700K.
5) Message boards : Proth Prime Search : Where are PPS mega k=15 to 99? (Message 126445)
Posted 73 days ago by Profile MyrskylyhtyProject donor
Fun fact:

The smaller 200K FFT size is actually slower than the 256K FFT size on my 7700K when using 4 threads. Using fewer threads is however faster.
6) Message boards : Proth Prime Search : Where are PPS mega k=15 to 99? (Message 126426)
Posted 73 days ago by Profile MyrskylyhtyProject donor
Next MEGAs are with larger n's? Why not with larger k's?


If PPS mega would go up to higher k's, it would probably be to PPSE territory (k=1201 to 9999) for consistency.

A quick test shows that FFT sizes (that determine the efficiency of the test) for current k's 11 to 1199 for n=3.6M are much smaller or the same than for the higher k's at the mega limit.

Starting Proth prime test of 11*2^3600003+1
Using all-complex FMA3 FFT length 200K, Pass1=640, Pass2=320, 4 threads, a = 3

Starting Proth prime test of 101*2^3600003+1
Using all-complex FMA3 FFT length 256K, Pass1=128, Pass2=2K, 4 threads, a = 3

Starting Proth prime test of 501*2^3600003+1
Using all-complex FMA3 FFT length 256K, Pass1=128, Pass2=2K, 4 threads, a = 7

Starting Proth prime test of 1199*2^3600003+1
Using all-complex FMA3 FFT length 256K, Pass1=128, Pass2=2K, 4 threads, a = 3

And then for the higher k's (n drops from 3.6M to ~3.32M):

Starting Proth prime test of 3999*2^3321917+1
Using all-complex FMA3 FFT length 256K, Pass1=128, Pass2=2K, 4 threads, a = 11

Starting Proth prime test of 6999*2^3321918+1
Using all-complex FMA3 FFT length 256K, Pass1=128, Pass2=2K, 4 threads, a = 5

Starting Proth prime test of 9999*2^3321915+1
Using all-complex FMA3 FFT length 256K, Pass1=128, Pass2=2K, 4 threads, a = 5


So IMO it might not be the best idea to move to higher k's yet. Sure, there is less iterations to do, but the smaller k's are more efficient. And I like the fact that the leading edge goes up faster :)
7) Message boards : Proth Prime Search : Where are PPS mega k=15 to 99? (Message 126422)
Posted 73 days ago by Profile MyrskylyhtyProject donor
Hey.

I'm adamantly waiting for PPS mega search to reach n=3.6M, since after that it will evidently start testing smaller k's that also have smaller FFT sizes.

However, on the stats page http://www.primegrid.com/stats_mega_llr.php, k's between 15 and 99 are missing. They are visible on PPS for up to n=3321992 (the mega limit). I can also find primes like 33*2^3570132+1 using the Primes by Project page.

Will those k's also start being tested at n=3.6M? What is the cause that we can only see k=11 and k=13 on the stats page?
8) Message boards : Storm message board (Message 126104)
Posted 77 days ago by Profile MyrskylyhtyProject donor
Thanks! Its been 10 months since my last prime, since I havent been testing the smallest T5K a lot. Now gonna go for my first mega!
9) Message boards : Storm message board (Message 125897)
Posted 79 days ago by Profile MyrskylyhtyProject donor
I think multithreading might be worth it for PPS mega, maybe PPS too. You can only find out by testing it out :)

Good luck all!
10) Message boards : Generalized Fermat Prime Search : DO YOU FEEL LUCKY? (Message 125650)
Posted 81 days ago by Profile MyrskylyhtyProject donor
I have no idea what's going on. 2.8M credit a task with 60% bonus? Just as I'm about to park @ 100M & do manual sving...


I think manual sieve will still give more credits. And in case it will be GFN23 project, GFN22 sieving results can be used for GFN23 for up to b=44,720.


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