[QUOTE=ET_;311657](Now that I think about it... which one would be faster?)[/QUOTE]
The one with a lower B1 is much faster, as for each additional prime to B1 you need to do a new exponentiation (i.e. a couple of squaring operations and multiplications) mod Mp. When extending B2, for each additional [U]cluster[/U] of primes that you add to B2 you need to do a (single one) multiplication mod Mp.

[QUOTE=LaurV;311694]The one with a lower B1 is much faster, as for each additional prime to B1 you need to do a new exponentiation (i.e. a couple of squaring operations and multiplications) mod Mp. When extending B2, for each additional [U]cluster[/U] of primes that you add to B2 you need to do a (single one) multiplication mod Mp.[/QUOTE]

That is true, but the modular multiplication on B2 are done on a much higher number of bits... That is the reason of my question.

Luigi

Chals,
Cohen has nothing to do with it. If you want to play that game, don't quote Jwb. "Everybody Knows" what he said- it is on the same page. Please don't take this as an attack on you personally, [B]but please leave the bard duties to daveiddy!
[/B]Just my 2¢.

Found a few lately:

[CODE]P-1 found a factor in stage #1, B1=810000.
UID: PageFault/boxen_01, M70002791 has a factor: 10476233014671785173315351[/CODE]

[URL="http://www.mersenne.ca/exponent.php?exponentdetails=70002791"]M70002791[/URL]

k = 3 x 5^2 x 19 x 79 x 761 x 2141 x 407959

[URL="http://www.mersenne.ca/exponent.php?exponentdetails=70003481"]M70003481[/URL]

[CODE]P-1 found a factor in stage #1, B1=810000.
UID: PageFault/boxen_01, M70003481 has a factor: 222473048199885240645001[/CODE]

k = 2^2 x 3 x 5^4 x 277 x 2731 x 280069

These aren't very smooth. Both could have been found with a ridiculous B1 of 2750. Perhaps I should start pre-screening for these?

[QUOTE=PageFault;312321]Found a few lately:

[CODE]P-1 found a factor in stage #1, B1=810000.
UID: PageFault/boxen_01, M70002791 has a factor: 10476233014671785173315351[/CODE][URL="http://www.mersenne.ca/exponent.php?exponentdetails=70002791"]M70002791[/URL]

k = 3 x 5^2 x 19 x 79 x 761 x 2141 x 407959

[URL="http://www.mersenne.ca/exponent.php?exponentdetails=70003481"]M70003481[/URL]

[CODE]P-1 found a factor in stage #1, B1=810000.
UID: PageFault/boxen_01, M70003481 has a factor: 222473048199885240645001[/CODE]k = 2^2 x 3 x 5^4 x 277 x 2731 x 280069

These aren't very smooth. Both could have been found with a ridiculous B1 of 2750. Perhaps I should start pre-screening for these?[/QUOTE]

FWIW, in the 84.4M range, there are at least (several tests left) three numbers factored with B1=60000=B2 or less, including M84,400,003. I am taking this 100k range to B1=1M (slowly) and saving files to do B2 on top of.

P-1 found a factor in stage #2, B1=530000, B2=9805000.
UID: Jwb52z/Clay, M57744637 has a factor: 256107633532327108861568647

87.727 bits

P-1 found a factor in stage #1, B1=530000.
UID: Jwb52z/Clay, M57731417 has a factor: 1322645848375959335562359

80.130 bits

P-1 found a factor in stage #1, B1=530000.
UID: Jwb52z/Clay, M57739921 has a factor: 174129453467924169651127

77.205 bits

P-1 found a factor in stage #2, B1=565000, B2=12006250, E=6.
UID: Jatheski/JTS_2, M56268371 has a factor: 445745465219441846607767554801 (98.492 bits)
k = 3960888304545388799400 = 2^3 × 3 × 5^2 × 47 × 599 × 8573 × 26041 × 1050331

Largest factor I found using P-1 :smile:

[QUOTE=Jatheski;312517]P-1 found a factor in stage #2, B1=565000, B2=12006250, E=6.
UID: Jatheski/JTS_2, M56268371 has a factor: 445745465219441846607767554801 (98.492 bits)
k = 3960888304545388799400 = 2^3 × 3 × 5^2 × 47 × 599 × 8573 × 26041 × 1050331

Largest factor I found using P-1 :smile:[/QUOTE]

Sorry for the double post but i cannot edit my previous reply...

Two weeks ago i found this one:

P-1 found a factor in stage #2, B1=535000, B2=[B]10967500[/B], E=6.
UID: Jatheski/JTS_2, M57252271 has a factor: 68943540478860569348473098497 (95.799 bits)
k = 602103106782092271488 = 2^7 × 11 × 53 × 521 × 1607 × [B]9636930871
[/B]

[QUOTE=Jatheski;312530]Sorry for the double post but i cannot edit my previous reply...

Two weeks ago i found this one:

P-1 found a factor in stage #2, B1=535000, B2=[B]10967500[/B], E=6.
UID: Jatheski/JTS_2, M57252271 has a factor: 68943540478860569348473098497 (95.799 bits)
k = 602103106782092271488 = 2^7 × 11 × 53 × 521 × 1607 × [B]9636930871
[/B][/QUOTE]

That is a monster B-S find... wow. I'm pretty sure you [URL="http://www.mersenne.ca/brent-suyama.php?s=b2m&o=d"]smashed the record[/URL].

Could you submit the result [URL="http://www.mersenne.ca/index.php?submitresults=1"]here[/URL] so that it appears on that list?