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drummers-lowrise
1) Message boards : Number crunching : 2019 Mega Primes (Message 134844)
Posted 2 days ago by Profile JeppeSNProject donor
And 64506894^131072 + 1 is next. /JeppeSN
2) Message boards : Number crunching : Transit of Mercury Across the Sun Challenge (Message 134808)
Posted 3 days ago by Profile JeppeSNProject donor
I was lucky as weather was good at the start of the transit. But after one hour it got cloudy. It IS pretty hard to spot.


Nice! Thanks for sharing this.


Yes, nice! I have to scroll up and down a bit to be certain what is dirt on my display and what is a planet, but then I do see it. /JeppeSN
3) Message boards : Number crunching : Suggestions for 2020 Challenges (Message 134747)
Posted 5 days ago by Profile JeppeSNProject donor
I agree with Yves.

The theoretical value of proving the conjecture that every odd k < 78557 has a Proth prime k*2^n + 1, so that the known Sierpiński number 78557 is necessarily the smallest one, is not that big. We would still not know if all of those k have infinitely many Proth primes, and there will still be a bunch of k above 78557 for which we cannot prove that they are not Sierpiński.

So the mathematical result that 78557 is the smallest Sierpiński number, does not give that much theoretical insight.

Finding out how many GFN-16 primes there are under a given B limit, or checking how many Fermat divisors there are in a given (k, n) rectangle, and comparing to theoretical heuristics, might be just as interesting for mathematics.

But generally, crunching primes does not prove very much, in fact.

/JeppeSN
4) Message boards : Number crunching : RunTime vs CPUTime (Message 134745)
Posted 5 days ago by Profile JeppeSNProject donor
so until the time that Mike updated the multithreading system, the runtime could be the same as the cpu time in the beginning.

I don't think it was, even for CPU tasks.

The question is how it is measured, and how accurately.

/JeppeSN
5) Message boards : Number crunching : error (Message 134596)
Posted 10 days ago by Profile JeppeSNProject donor
You came on the list with a task from another of your computers now, however (14:44:50 UTC, it seems). It was run single-threadedly. /JeppeSN
6) Message boards : Fermat Divisor Search : Fermat Divisor Search (Message 134522)
Posted 12 days ago by Profile JeppeSNProject donor
PPSE is going to reach n=1.55M where the DIV search started with k: 1323, 2187, 3125, 3267, and 3375. New work has been loaded to PPSE, up to n=1.56M, and you can see for 3125 and 3375 that there is a "hole" that DIV exhausted already. For the other three k, you cannot see it as easily since the odd n values still need to be crunched (DIV only did the even n for 1323, 2187, 3267).

In a sense, it is not until PPSE is past n=1.55M that we can conclude that these five k are "done".

/JeppeSN
7) Message boards : Number crunching : Transit of Mercury Across the Sun Challenge (Message 134520)
Posted 12 days ago by Profile JeppeSNProject donor
Finishing just one single task is incredibly hard. It will take centuries before these Sierpiński-related problems/conjectures are solved. /JeppeSN

I thought that as well when I started participating here. The leading edge of SoB was lower than PSP is now. Now a decade later and the leading edge of SoB is more than double it was for my first SoB workunits. Great progress continues to be made on these projects.


I absolutely agree great progress continues to be made. In the thread id=7356, Yves Gallot has two posts on when the primary conjecture project here, the SoB, might be completed. I think it might take even longer. /JeppeSN
8) Message boards : Number crunching : Transit of Mercury Across the Sun Challenge (Message 134505)
Posted 12 days ago by Profile JeppeSNProject donor
Finishing just one single task is incredibly hard. It will take centuries before these Sierpiński-related problems/conjectures are solved. /JeppeSN
9) Message boards : Number crunching : Suggestions for 2020 Challenges (Message 134500)
Posted 13 days ago by Profile JeppeSNProject donor
OK, here are some suggestions:

  • DIV, Fermat Divisor Search (LLR)
  • 321 (LLR)
  • SoB, Seventeen or Bust (LLR)
  • Cullen+Woodall combined (LLR)
  • GFN-16 (Genefer, "easiest" GPU Top 5000 primes)
  • GFN-20 (Genefer, let 2020 be the year of the GFN-20)

/JeppeSN

10) Message boards : Proth Prime Search : PPS-MEGA: Smaller FFT longer crunch time ? (Message 134423)
Posted 14 days ago by Profile JeppeSNProject donor
True. But when testing, you could start LLR from the command line with the same number, on different FFT sizes, and on both computers. Or you could do it with both a small k candidate and a large k. That might shed some light on why big FFT sizes seem to give shorter run-times on the live tasks. /JeppeSN


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