[QUOTE=James Heinrich;298639]For those who are fascinated by P-1 factors found thanks to the Brent-Suyama extension, I now have a list of known ones here:
[url]http://mersenne-aries.sili.net/brent-suyama.php[/url][/QUOTE]And, vaguely related, there's now a list of the "smoothest" P-1 factors:
[url]http://mersenne-aries.sili.net/smooth.php[/url]

Smoothest is defined in this context as the smallest ratio of minimum-required B2 / factor-bits.

For example:
[url=http://mersenne-aries.sili.net/M31001941]M31,001,941[/url] has factor: 16861341412139695521233727186051728863
k = 3 × 19 × 37 × 43 × 113 × 421 × 2749 × 5639 × 10331 × 12239 × 32159
B2= 32,159
factor = 123.67 bits


Note: as with the Brent-Suyama tool, I'm still populating my database with the needed info on k factorization and thereby B1/B2, so the data will get better over the next few weeks.

I know that someone has probably asked this question dozens of times over the life of the project, but I don't seem to find the exact thing I'm wondering. How unusual, or not, is it to find a factor in a P-1 test in Stage 1 just after the Stage 1 GCD finishes so it doesn't need to do the stage 2 primes? Since I have had my new laptop, I've found a factors at this point.

James, if you need data, I can go through old results.txt and extract my P-1 factors along with B1 / B2 and the ram allocated.

Jwb52z, I just found a stage 1 factor ... only the second one in about 12 years of running prime ...

[CODE]P-1 found a factor in stage #1, B1=605000
M57077831 has a factor: 1712714925748426197673681[/CODE]

That's exactly why I was asking. I don't think I've found more than 5 during the entire run of the project that I've participated in, I stopped for a while once, since it started. Maybe it's just more frequent feeling because of computer speeds being increased now compared to the past.

[QUOTE=Jwb52z;298836]I know that someone has probably asked this question dozens of times over the life of the project, but I don't seem to find the exact thing I'm wondering. How unusual, or not, is it to find a factor in a P-1 test in Stage 1 just after the Stage 1 GCD finishes so it doesn't need to do the stage 2 primes? Since I have had my new laptop, I've found a factors at this point.[/QUOTE]
I'd say... with default bounds by Prime95, it's probably around 40-60 S1-S2, or maybe a bit lower. It shouldn't be any less than 25-75.
[QUOTE=PageFault;298837]James, if you need data, I can go through old results.txt and extract my P-1 factors along with B1 / B2 and the ram allocated.

Jwb52z, I just found a stage 1 factor ... only the second one in about 12 years of running prime ...

[CODE]P-1 found a factor in stage #1, B1=605000
M57077831 has a factor: 1712714925748426197673681[/CODE][/QUOTE]
Why not just [URL="http://mersenne-aries.sili.net/index.php?submitresults=1"]upload/submit your results[/URL] to his website? That's what the rest of us do.



Edit: Note to James, the link you provided for smooth talks about regular-smoothness, but B1 and B2 are actually power-smooth bounds, as axn described earlier. Probably best solution is that someone edits the wiki page to include both descriptions. (Or you could link to Wikipedia's [URL="http://en.wikipedia.org/wiki/Smooth_number"]article[/URL], which includes the powersmooth definition.)

[QUOTE=Jwb52z;298836]I know that someone has probably asked this question dozens of times over the life of the project, but I don't seem to find the exact thing I'm wondering. How unusual, or not, is it to find a factor in a P-1 test in Stage 1 just after the Stage 1 GCD finishes so it doesn't need to do the stage 2 primes? Since I have had my new laptop, I've found a factors at this point.[/QUOTE]Overall, it's not that uncommon. From a recent copy of my data, I have record of 3058 P-1 factors, of which 691 (23%) were stage 1 and 2367 were stage 2 (77%). If you care to have that broken down by range:[code]Range Stage1 Stage2
All 691 2367
0M-10M 295 1529
10M-20M 179 453
20M-30M 13 85
30M-40M 18 25
40M-50M 39 97
50M-60M 138 173
60M+ 9 5[/code]Personally, I've found 21 factors in stage1 on my main machine in the last 5 months, and 79 on my other machine in the last 3 years.

[QUOTE=PageFault;298837]James, if you need data, I can go through old results.txt and extract my P-1 factors along with B1 / B2 and the ram allocated.[/QUOTE]If you have old results.txt, please submit them all to [url]http://mersenne-aries.sili.net[/url] if you haven't already. Any data I need will be automatically parsed from that.

Ok James, will do ...

You find lots of factors. I have a spreadsheet somewhere and my batting average for P-1 is below average, around .03 or so. It is in recent months that I put a core on P-1 (so far 2/34 successes), the bulk were done in the course of first time testing.

I added some ram last week but it doesn't seem to change the bounds. It does run faster, cutting stage 2 time from ~30 to 23 hours. What is noticeable is the # of relative primes per batch - this increased to 72 from 40. Maybe my box is too old - Pentium D 3.4 GHz with 1920 MB allocated to prime95.

[QUOTE=PageFault;298843]I added some ram last week but it doesn't seem to change the bounds... # of relative primes per batch - this increased to 72 from 40.[/QUOTE]Your box is on the older side, but can still provide some useful contribution. Moreover, your success rate doesn't depend a whole lot on the speed of your box, although obviously you won't push through nearly as many exponents.

I tend to find a lot of factors relative to my processing power because my older box (which is still an i7-920 with 12GB) is running through [url=http://mersenne-aries.sili.net/p1small.php]previously-badly-done P-1[/url] assignments. For exponents in that range it's no problem to run a full 480 relative primes at once with a modest amount of RAM, and my i7-920 can push through about 3 exponents an hour [I]per core[/I].

My main box can also run 480/480 RPs at once, but that takes about 12GB for a "current" exponent in the 55M range.

James, I looked at your link, P-1 poorly or not done. This is interesting ... some questions:

I clicked on "get exponents" but nothing happens, no matter what I selected. Maybe because I turned off alot of crap in IE ...

If I were to get exponents, how to submit results - manual or primenet? Do I get credited?

Thanks,

PF

If you fill in a starting exponent you'll get some data. Or just click one of the ranges from the "worst-done ranges" list. For example, [url=http://mersenne-aries.sili.net/p1small.php?prob=3&min=8300000&max=8400000&onlystage1=0&ignorenop1=0&showassigned=0]M8,300,000[/url]. You'll see the list of badly-done P-1, either with no stage-2, or ill-chosen bounds, either way with an effective probability of <3% (compared to standard ~5-6%). Copy-past as many assignments as you like from the left column (e.g. "Pfactor=1,2,8317429,-1,64,2") into your worktodo.txt (after stopping Prime95), restart Prime95 and let it get assignment IDs for all the work you just added. You'll certainly get PrimeNet credit for any work you do that way (Prime95 will still automatically report results when complete, you're just assigning them manually).

Note: working in this range you're not saving anyone any L-L or DC effort. But you will eventually save someone some ECM effort with any factors found. And finding factors is fun! :smile: