[QUOTE=GP2;469571]The others are only (very) probably-fully-factored. The Primenet database should probably distinguish between the two cases, as Mersenne.ca already does.[/QUOTE]

The database does distinguish but needs to be updated manually as the server does not store certificates.

Sorry if this is offtopice, but I wanted to try PRIMO as I've never used it before.

I tried it on a (Sandy-Bridge based) 1x Xeon 2620 (6c12t, 2GHz-ish) with 16GB ECC RAM and Ubuntu 16.04 LTS
I used 12 threads and sieve 5000 - 25 bits (is there a guide on what parameters to use? I couldn't find it in the readme or FAQ?)

So I tried some of the standard input files and added M8243cofactor as an exercise
10^55+21 - 0.13s
10^700+7 - 12.57s
10^999+7 - 61s
M8243-cofactor - 1826s

They were all prime (as known/expected) and I got a bunch of files now :confused2:
.in (the Input, that makes sense)
.wr (Work Report?)
.cr (Certificate Report?)
.out (Primality Certificate?)
So which ones do you need to upload/report in case it is a new test and where do you upload them?

[QUOTE=VictordeHolland;469589]Sorry if this is offtopice, but I wanted to try PRIMO as I've never used it before.

I tried it on a (Sandy-Bridge based) 1x Xeon 2620 (6c12t, 2GHz-ish) with 16GB ECC RAM and Ubuntu 16.04 LTS
I used 12 threads and sieve 5000 - 25 bits (is there a guide on what parameters to use? I couldn't find it in the readme or FAQ?)

So I tried some of the standard input files and added M8243cofactor as an exercise
10^55+21 - 0.13s
10^700+7 - 12.57s
10^999+7 - 61s
M8243-cofactor - 1826s

They were all prime (as known/expected) and I got a bunch of files now :confused2:
.in (the Input, that makes sense)
.wr (Work Report?)
.cr (Certificate Report?)
.out (Primality Certificate?)
So which ones do you need to upload/report in case it is a new test and where do you upload them?[/QUOTE]

My test of M8243-cofactor took 1400 seconds on a o/c 4770k. I uploaded the certificate -- yes the .out file -- to [url]http://www.factordb.com/result.php[/url].

I used the default parameters, but on big jobs I max them out.

[QUOTE=paulunderwood;469591]My test of M8243-cofactor took 1400 seconds on a o/c 4770k. I uploaded the certificate -- yes the .out file -- to [URL]http://www.factordb.com/result.php[/URL].

I used the default parameters, but on big jobs I max them out.[/QUOTE]
Thx!

Yeah, my time seems to be what is expected, considering it is 2 generations older and the GHz*cores is lower than yours. Xeon 2620 (6c*2.3GHz=13.8) vs. your 4770k (4c*4GHz??=16?).

[QUOTE=GP2;469584]Mersenne.org is now listing PRP residues in a separate Cofactor PRP section. Excellent.[/QUOTE]Mersenne.ca now automatically imports PRP results from mersenne.org (overnightly), and the exponent details page has an additional section with the PRP logs from PrimeNet.

The 318th fully-factored or probably-fully-factored Mersenne number with prime exponent (not including the Mersenne primes themselves) is [M]M20521[/M].

I found the most recent factor, and Oliver Kruse did the PRP test.

As usual, needs a Primo certificate, if anyone wants to do it.


As is usually the case for small exponents, the ECM curve that found the factor actually output "Cofactor is a probable prime", although I didn't notice this until after the fact.

So the ECM code automatically does a PRP test, at least for small exponents, and calculates a residue. Perhaps in future versions it could send that residue result straight to the database.

[QUOTE=GP2;470064]The 318th fully-factored or probably-fully-factored Mersenne number with prime exponent (not including the Mersenne primes themselves) is [M]M20521[/M].

I found the most recent factor, and Oliver Kruse did the PRP test.

As usual, needs a Primo certificate, if anyone wants to do it.[/QUOTE]

I'm certifying it now... :cool:

[URL="http://www.factordb.com/index.php?id=1100000001055837715"]Certification of the M20521 cofactor[/URL] is complete. This [URL="http://primes.utm.edu/primes/page.php?id=123954"]prime[/URL] makes it into the [URL="http://primes.utm.edu/top20/page.php?id=49"]top20[/URL] Mersenne cofactors. :thumbs-up:

I notice something amusing WRT fully-factored Mp's whose last factor is a PRP-cum-certified-prime: The tables, e.g.for [url=http://www.mersenne.ca/exponent/20521]20521[/url] or even [url=http://www.mersenne.ca/exponent/397]397[/url] list all but the last factor as "known prime factors" but describe the remaining cofactor as a "certified-prime." In the case of 397, this affects the description in the table of [url=http://www.mersenne.ca/manyfactors.php]Top Mersenne exponents with the most known factors[/url], which says M397 has only 8 known prime factors! Since the last factor is only 31 decimal digits, the primality would seem to beyond cavil...

[QUOTE=Dr Sardonicus;470106]I notice something amusing WRT fully-factored Mp's whose last factor is a PRP-cum-certified-prime: The tables, e.g.for [url=http://www.mersenne.ca/exponent/20521]20521[/url] or even [url=http://www.mersenne.ca/exponent/397]397[/url] list all but the last factor as "known prime factors" but describe the remaining cofactor as a "certified-prime." In the case of 397, this affects the description in the table of [url=http://www.mersenne.ca/manyfactors.php]Top Mersenne exponents with the most known factors[/url], which says M397 has only 8 known prime factors! Since the last factor is only 31 decimal digits, the primality would seem to beyond cavil...[/QUOTE]

And [M]M11[/M] has only "one" known factor, even though it's actually the product of 23 × 89.

For the sake of consistency we always omit that final cofactor, which is usually both enormous and composite.

[QUOTE=Dr Sardonicus;470106]In the case of 397, this affects the description in the table of [url=http://www.mersenne.ca/manyfactors.php]Top Mersenne exponents with the most known factors[/url], which says M397 has only 8 known prime factors! Since the last factor is only 31 decimal digits, the primality would seem to beyond cavil...[/QUOTE]There are indeed 9 factors for M397, the smallest 8 of which are listed on the [url=http://www.mersenne.ca/exponent/397]exponent page[/url], the last one (6597485910270326519900042655193) is only shown on demand on the [url=http://www.mersenne.ca/prp.php?show=2&min_exponent=0&max_exponent=1000#M397]PRP page[/url].

I have updated the [url=http://www.mersenne.ca/manyfactors.php]many-factors page[/url] to take these kind of PRP last-factors into account, the affected exponents are shown in red.
And yes, in many cases with smaller exponents the percentage-known won't quite reach 100% due to rounding.