Please visit donation page to help the project cover running costs for this month

Toggle Menu

Join PrimeGrid

Returning Participants


Leader Boards



1) Message boards : Number crunching : Credit Milestones (Message 149560)
Posted 57 days ago by Profile GellyProject donor
1 billion. hilarious.
2) Message boards : The Riesel Problem : K=2293 reported in top 5k page (Message 148973)
Posted 82 days ago by Profile GellyProject donor
Hmm, US privacy laws are liberal. With 5 minutes of google I found out his age, which party he is a registered voter for, the house he lives in and which sector he's probably working in and a rough estimate of the income.


I sure hope I am misinterpreting this as a "jokey" threat, because if it was intended that way it was in poor taste. At the end of the day, Ryan Propper did all his own sieving work and found the prime with no assistance from Primegrid. It may be a bit tasteless from our perspective, but considering he's helped the conjecture with just his own work, he is a valuable resource to the prime finding community and should be respected as such.

Primegrid is meant to be collaborative, not competitive, and if we fail to see that in terms of this situation, we become an enemy of prime finders everywhere for no other reason than sour grapes. Don't do this.
3) Message boards : Number crunching : Credit Milestones (Message 147650)
Posted 118 days ago by Profile GellyProject donor
Obviously posting Credit Milestones and acquired badges is a job for the PG web server. It could be a front page item like the newly reported primes, under the list of Top Crunchers. Maybe with links to the latest Credit Milestones & Badges forums. What constitutes a milestone could be a matter of preference. Comments anyone?

pick whatever numbers you like, honestly. some people have grander objectives than others - i'll be waiting to post 1B credit instead of doing updates on 800m, 900m, etc. i like people being able to celebrate whatever arbitrary lines they like and not having it be a server announcement. it's more human that way, whatever that means.
4) Message boards : Antarctic Crunchers message board (Message 147591)
Posted 121 days ago by Profile GellyProject donor
wooooo, spring break
5) Message boards : Number crunching : Good Riddance 2020! Challenge (Message 147564)
Posted 122 days ago by Profile GellyProject donor

Yawn...... these challenges have just descended into who can hire the most pc's to crunch with. I don't even bother looking at the ranks any more.

Original post was pretty bitter. All I'll say is this:

It's always been "pay-to-win". The difference is I don't have to keep the expensive hardware in my apartment.
6) Message boards : Number crunching : Credit Milestones (Message 147304)
Posted 134 days ago by Profile GellyProject donor
500M. Blasted past it while running some TSC instances against WW 1.05
7) Message boards : General discussion : Extended generalized Fermat prime? (Message 146710)
Posted 151 days ago by Profile GellyProject donor
ECPP is achingly slow. There is a reason the official version of primo only goes up to 50k decimal digits. The current record, 40k digits, was set by Paul Underwood on 48 thread hardware that took more than a year and was nothing to sneeze at. My 3970x threadripper, a 32 core, 64 thread beast, takes two weeks to months to prove candidates in the 20k digit range.

As a rule of thumb, when you double the amount of digits in the number to be tested, the time it takes goes up 16 to 32 times, depending on how lucky you are. It will likely be years before Paul proves the next big step in ECPP (the smallest unproven repunit, 49k digits), and I'm sure he either got a 3990x (64 cores!) or maybe even doshed out on EPYC.

100k digits, on current hardware with current methods, would take decades.
8) Message boards : General discussion : b^n - b^m - 1 primes (Message 145537)
Posted 176 days ago by Profile GellyProject donor
It actually would not be a Proth number. For a generalized Proth number k*b^n + 1 (or Thorp, k*b^n-1), the requirement is that k < b^n. For the rearrangement you provided, where k = b^(n-m)-1, it will not necessarily be true that k < b^m (such as when n-m > m)

Edit: Concerning your original question, programs usually have a limit on the size of k that are acceptable to test. With a different form, you don't have to fight with the k requirement.
9) Message boards : General discussion : Current number of tests for a prime? (Message 145013)
Posted 191 days ago by Profile GellyProject donor
The only number I know for sure, based on empirical evidence, is that finding or DCing an SGS prime tends to happen after about 15k tasks. The other ones are a lot harder to get good numbers for, since they happen more rarely.
10) Message boards : Number crunching : Sieve for palindromic primes? (Message 144796)
Posted 200 days ago by Profile GellyProject donor
Doing a lot of hunting on MersenneForums, Batalov indicated that the sieve he wrote was "quick n' dirty in Pari", PARI/GP being a mathematical programming/scripting language.

The reason that they are a little bit more convoluted (10^(2n)+999*10^(n-1)+1) is because if the form is too simple, it's liable to be divisible by numbers for a vast majority of exponents - see for a similar example.

I'm not certain on the precise particulars of how you'd quickndirty sieve in Pari. It looks to be a form that's a little more complicated than just figuring out what n lead to being non-prime for different p, like what you can do for k*b^n +- 1 with BSGS.[/url]

Next 10 posts
[Return to PrimeGrid main page]
Copyright © 2005 - 2021 Rytis Slatkevičius (contact) and PrimeGrid community. Server load 6.48, 5.59, 5.03
Generated 17 May 2021 | 11:07:53 UTC