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drummerslowrise

1)
Message boards :
Seventeen or Bust :
The SoB Double Check is DONE!!!
(Message 133618)
Posted 5 days ago by Myrskylyhty
So, still a chance that the DC yields a prime ;)

2)
Message boards :
Fermat Divisor Search :
Fermat Divisor Search
(Message 133397)
Posted 13 days ago by Myrskylyhty
So, 24 days for 4 %, which translates into 6 days per 1 %.
That's 576 days left, which means we would finish on 28.4.2021.
But I estimate that the challenge + multithread efficiency + new hardware could mean that we finish during next year. Let's see :)

3)
Message boards :
Fermat Divisor Search :
Fermat Divisor Search
(Message 133016)
Posted 23 days ago by Myrskylyhty
I did a bit of checking into FFT size increases:
k=11:
FFT length 288K: n = 4,713,563
FFT length 320K: n = 5,262,883
FFT length 384K: n = 5,865,205
FFT length 400K: n = 7,008,845
FFT length 480K: n = 7,288,505
FFT length 512K: n = 8,694,807
k=49:
FFT length 288K: n = 4,431,064
FFT length 320K: n = 4,945,072
FFT length 384K: n = 5,512,082
FFT length 400K: n = 6,585,098
FFT length 480K: n = 6,847,102
FFT length 512K: n = 8,165,124
FFT length 576K: n = 8,718,132

4)
Message boards :
Fermat Divisor Search :
Fermat Divisor Search
(Message 132702)
Posted 34 days ago by Myrskylyhty
Ooh, more fancy tables.
How often will you update that table? 1 % or some other increment?

5)
Message boards :
Storm message board
(Message 132128)
Posted 55 days ago by Myrskylyhty
Maybe Robish you could use up some of that Irish luck and grab a GFN18 or a few :D

6)
Message boards :
Storm message board
(Message 132127)
Posted 55 days ago by Myrskylyhty
It's also been like 8 months since last GFN18! :D
Between 20162018 it was a prime every few months (21 primes total). That translates to that this we should have found like 5 primes normally.

7)
Message boards :
Storm message board
(Message 127761)
Posted 221 days ago by Myrskylyhty
When in doubt, use the SIunits:
2 gigacredits
Congrats!

8)
Message boards :
Storm message board
(Message 126649)
Posted 244 days ago by Myrskylyhty
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 LucasLehmer 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 LucasLehmerRiesel 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.

9)
Message boards :
Proth Prime Search :
Where are PPS mega k=15 to 99?
(Message 126563)
Posted 246 days ago by Myrskylyhty
PPS Mega started on PRPNet, that's where those lowk candidates were tested. We never felt any great need to DC them. PPS Mega was then n=3.322M3.6M.
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=1199 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=1599 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=111199 will start being tested in MEGA at n=3.6M+ the next time we need to load work there"

10)
Message boards :
Proth Prime Search :
Where are PPS mega k=15 to 99?
(Message 126509)
Posted 247 days ago by Myrskylyhty
Here's some benchmarks on FFT size = 200K on the i77700K (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 counterintuitive. So keep this in mind when selecting multithreading for your machine. I'm definately going with t1 on the i77700K.

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