[QUOTE=GP2;502562]TJAOI didn't miss that factor, he simply hadn't reached it yet.

When TJAOI works on a bit level, he finds factors in increasing numerical order.

From your link, TJAOI found the factor 46877384547124608047 on 2018-10-03. Recently he has been finding factors like [URL="https://www.mersenne.org/report_exponent/?exp_lo=18216343&exp_hi=&full=1"]51742865878987223449[/URL] on 2018-12-05. Your factor was 60339186474018340969, which you found on 2018-11-03. TJAOI will complete the 66-bit level when he reaches 2^66 = 73786976294838206464. All of these factors are within the range of TF 65–66.[/QUOTE]

It seems like a very inefficient way of doing it. He must find primes q in the current range of increasing order and then factor q-1 = 2*p1*p2*...*pk and then check if q is a factor of each Mp1, Mp2 to Mpk ?

[QUOTE=ATH;502622]It seems like a very inefficient way of doing it. He must find primes q in the current range of increasing order and then factor q-1 = 2*p1*p2*...*pk and then check if q is a factor of each Mp1, Mp2 to Mpk ?[/QUOTE]

In the very long "[URL="https://www.mersenneforum.org/showthread.php?t=19014"]User TJAOI[/URL]" thread there is some discussion and speculation about his methodology.

His progress is pretty rapid, so either he's using an efficient method or he has enormous resources.

If anyone cares, I have a small summary page on TJAOI's activity here:
[url]https://www.mersenne.ca/tjaoi.php[/url]

He's very regular, currently spitting out 3 sequential days of ~2000 factors, then 3 days break, then a handful of much-larger factors, and repeat that cycle every week.

[QUOTE=James Heinrich;502692]If anyone cares, I have a small summary page on TJAOI's activity here:
[URL]https://www.mersenne.ca/tjaoi.php[/URL]

He's very regular, currently spitting out 3 sequential days of ~2000 factors, then 3 days break, then a handful of much-larger factors, and repeat that cycle every week.[/QUOTE]

I looked at your link above. He's running a pattern. Is he using [I]mfaktc[/I] to do this, or something else?

Something else. You can find more details about it in the above-linked thread, including [url=https://www.mersenneforum.org/showpost.php?p=502828&postcount=461]a recent post[/url] showing the general technique.

[QUOTE=James Heinrich;502839]Something else. You can find more details about it in the above-linked thread, including [URL="https://www.mersenneforum.org/showpost.php?p=502828&postcount=461"]a recent post[/URL] showing the general technique.[/QUOTE]


[CODE]q=10^3;
while(q<10^5,
v=factorint(q-1)~[1,];
for(i=1,#v,
if(v[i]<10^9&&Mod(2,q)^v[i]==1,
print(q" divide 2^"v[i]"-1");
break
)
);
until(Mod(q,8)==1||Mod(q,8)==7,
q=nextprime(q+1)
)
)[/CODE]
I can follow a little of this. It's a language I've not seen before. :no:

[QUOTE=storm5510;502875]I can follow a little of this. It's a language I've not seen before. :no:[/QUOTE]

I think it's [URL="https://pari.math.u-bordeaux.fr/"]PARI/GP[/URL]

[QUOTE=GP2;502884]I think it's [URL="https://pari.math.u-bordeaux.fr/"]PARI/GP[/URL][/QUOTE]

Interesting. Everything I know is antiquated. Pascal, Cobol, Fortran, and, shall I say it, B.A.S.I.C. All of these, I learn at the local community college when I went there back in the late '80's and early '90's. There was also Assembly Language. That sailed over my head.

I have experimented with .Net Framework and had some success. All of this is so vast. I have Visual Studio 2017 installed now. I've not spent much time with it though.

Sorry for going [U]off-topic[/U].:blush:

[QUOTE=storm5510;502889]Interesting. Everything I know is antiquated. Pascal, Cobol, Fortran, and, shall I say it, B.A.S.I.C. All of these, I learn at the local community college when I went there back in the late '80's and early '90's. There was also Assembly Language. That sailed over my head.

I have experimented with .Net Framework and had some success. All of this is so vast. I have Visual Studio 2017 installed now. I've not spent much time with it though.

Sorry for going [U]off-topic[/U].:blush:[/QUOTE]
I think it would be good practice for such code posts to include a comment at the first line in the relevant syntax, identifying the language (and perhaps even compatible version number, & OS if relevant). Computing has become such a Babel over the decades, almost no one can know them all by sight.
Assembly language is great fun, especially when execution time is strictly limited by the necessity to perform all functions within a short time for real time control of robotics with slow processors (think half-millisecond for a well crafted 16 bit multiply via a subroutine, 2/3 millisecond for a 28 bit input square root, built from shift, add, subtract, and conditionals). Or when squeezing out a bit more GIMPS performance from a new flavor of chip, as Woltman routinely does.

I might be getting access to a multi-GPU system in the not-too-distant future and have a few questions:

1. It's my understanding that I need an mfaktc instance for each GPU. Is there a way to tell mfaktc to point to a certain folder, or do I need separate copies of mfaktc for each instance?

2. For CLI-only operating systems, mfaktc should work with a terminal multiplexer like tmux or GNU Screen, right?

Thanks!

[QUOTE=ixfd64;503594]I might be getting access to a multi-GPU system in the not-too-distant future and have a few questions:

1. It's my understanding that I need an mfaktc instance for each GPU. Is there a way to tell mfaktc to point to a certain folder, or do I need separate copies of mfaktc for each instance?

2. For CLI-only operating systems, mfaktc should work with a terminal multiplexer like tmux or GNU Screen, right?

Thanks![/QUOTE]

1. I create a directory for each mfaktc instance, and change to that directory to run mfaktc. I actually symlink the binary to the one I compile myself.

2. Yes, I run it in screen. It should work fine in tmux, too.