[QUOTE=lycorn;263805]Not quite right.
What is actually paralelized is the FFT algorithm. Both Stage 1 and 2 use FFTs to perform the calculations, so both Stages might benefit from the FFT paralelization (multi-threading). What can´t be paralelized, IIRC, are the GCD computations performed at the end of each Stage.[/QUOTE]Not quite right. :wink:

Stage 2 could, [i]in principle,[/i] be parallelized by running disjoint ranges of B2 between B1 and B2_max on separate threads, each thread performing its own GCD at the end of the range.

Whether anyone has coded for this approach is another matter entirely.

Paul

[QUOTE=xilman;263827]Stage 2 could, [i]in principle,[/i] be parallelized by running disjoint ranges of B2 between B1 and B2_max on separate threads, each thread performing its own GCD at the end of the range.[/QUOTE]

Or - again in principle - the result of each of the parallel computations could be multiplied together, allowing just a single GCD at the end.

From whatsnew.txt;

[CODE]2) Starting in build 2, P-1 work will display the chance of finding a factor.
The worktodo.txt line must include how_far_factored using the new syntax:
Pminus1=k,b,n,c,B1,[COLOR=Red][B]B2[/B][/COLOR][,how_far_factored][COLOR=Red][B][,B2_start][/B][/COLOR][,"factors"][/CODE]That's what I was thinking about.

[QUOTE=xilman;263827]Not quite right. :wink:
[/QUOTE]

Fair enough :bow:.
I took lorgix´s post to mean [U]only[/U] Stage 2 could be parallelized.

Any idea what Axon is doing, with 100% success on 2208 P-1s?
[url]http://v5www.mersenne.org/report_top_500_P-1/[/url]

Yep.

[URL]http://www.mersenneforum.org/showthread.php?t=15690[/URL]

Big case of same problem I have with TF: Server assumes factors found are from P-1!

Here I come...anyone wanna join me???
 

I have started to move PCs over to P-1 with the goal of having at least 20 cores and sustaining a rate of 10 completions per day by early August.
:batalov:

I will have 3 quads with all 4 cores doing P-1
Several Dual Cores - the newer ones with both cores assigned and the older slower ones with 1 core P-1 and 1 core TF
and 1 PIV.

I believe with "Memory=" now working at the Worker level
AND
the ability to set HighMemWorkers by time of day

I should be able to balance the work so even the quads can have decent thruput with all 4 cores doing P-1 limiting them to 2 cores in Stage 2 most of time with 3 cores only as needed to keep up.

I'll let the masses know how well this plan works but as long as the thruput is decent I plan to keep it this way at least for the remainder of 2011.

Petrw1, you are pulling a judo throw on me...following me, then going further...since I'm doing LL and CUDA TF, and it sounds like you may not be, but I'm doing as much P-1 as my memory will support.

Check out my P-1 numbers....most of those factors are P-1 factors, just a few TF...

I would like to see a list of P-1 factors found for exponents 40-60M,
or more concisely, the frequency f(x) of them exceeding the TF
bit limit by x bits.

Any ideas?

David

[QUOTE=davieddy;266542]I would like to see a list of P-1 factors found for exponents 40-60M,
or more concisely, the frequency f(x) of them exceeding the TF
bit limit by x bits.

Any ideas?

David[/QUOTE]

The [url=http://mersenne.org/report_factors/]known factors[/url] report has an option to specify a minimum factor depth. Given a list of factors exceeding the TF bit limit, you could calculate the smoothness of k for each one, to determine whether it could plausibly have been found with P-1.