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Madpoo 2015-10-21 15:16

[QUOTE=sdbardwick;413237][URL="http://www.mersenne.org/report_exponent/?exp_lo=37952297&full=1"]We matched.[/URL] -As expected, given the different shifts noted by Madpoo.[/QUOTE]

And thanks for doing that... saved me from doing the triple-check myself. :smile:

0PolarBearsHere 2015-10-22 05:39

[QUOTE=richs;413128]My DC of 35939129 didn't match. Anyone like to TC it?[/QUOTE]

Matched your one.

cuBerBruce 2015-10-22 17:25

[QUOTE=Madpoo;412980]52 of these below 38M. End result will be that, whatever the outcome, at least one of these previously "spotless" CPU's will have a bad result added to their account, which will hopefully feed into our strategic double checking:
[CODE]exponent worktodo
...
35795849 DoubleCheck=35795849,71,1
36056633 DoubleCheck=36056633,71,1
...
[/CODE][/QUOTE]

I got a match with one of the prior results with each of these two exponents.

Edit: I'll also note that richs's residue for M35939129 was verified.

richs 2015-10-23 03:31

Thanks for pointing that out. That was a quick turnaround.....

0PolarBearsHere 2015-10-23 08:12

[QUOTE=richs;413419]Thanks for pointing that out. That was a quick turnaround.....[/QUOTE]

I put yours at the top of my work queue. My first time 67M and 72M exponents weren't going to go anywhere.

cuBerBruce 2015-10-23 15:44

[QUOTE=Madpoo;413184]Here's more. From machines with at least a 3:1 bad:good ratio, using the "by calendar year" method:
[CODE]exponent Bad Good Unk Sus Solo Mis worktodo
...
51981047 7 2 11 8 11 8 DoubleCheck=51981047,73,1
...
[/CODE][/QUOTE]

I took this one.

bloodIce 2015-10-23 18:45

[QUOTE=cuBerBruce;412282]My residue did not match for M42003697.[/QUOTE]

[QUOTE=Madpoo;412352]As weird as this sounds, that's exactly what I like to hear. :smile: Strange to be rooting for *mis* matched residues with these.[/QUOTE]

The exponent M42003697 has a factor: 64458145045944198395681. I still wonder why we do not factor more, especially in cases like this. One big iron would have found the factor in less than a day...

cuBerBruce 2015-10-23 20:29

[QUOTE=bloodIce;413487]The exponent M42003697 has a factor: 64458145045944198395681. I still wonder why we do not factor more, especially in cases like this. One big iron would have found the factor in less than a day...[/QUOTE]

Well, my LL test only took a little over 2 days (using 4 cores). I don't think in general it's worth factoring such small exponents up to 76 bits. Well, thanks anyway for making my Results page a little less yellowy. :smile:

Mark Rose 2015-10-23 20:39

[QUOTE=bloodIce;413487]The exponent M42003697 has a factor: 64458145045944198395681. I still wonder why we do not factor more, especially in cases like this. One big iron would have found the factor in less than a day...[/QUOTE]

Because the same GPU ought to be able to LL it faster than doing the higher levels of TF...

Prime95 2015-10-23 20:44

I took the remaining exponents in madpoo's last post:

[CODE]
DoubleCheck=52210813,73,1
DoubleCheck=55443329,73,1
DoubleCheck=55894291,73,1
DoubleCheck=56542063,73,1
DoubleCheck=56699557,73,1
DoubleCheck=57740621,73,1[/CODE]

VBCurtis 2015-10-23 21:02

[QUOTE=bloodIce;413487]The exponent M42003697 has a factor: 64458145045944198395681. I still wonder why we do not factor more, especially in cases like this. One big iron would have found the factor in less than a day...[/QUOTE]

It takes, on average, n factoring runs from n-1 bits to n bits to find a factor. So, rather than ask how long it would take to find *this* factor, estimate how long it would take to factor 75 numbers from 75 bits to 76 bits to expect to find one factor. Expectation may be higher than 75 runs, since P-1 factoring finds some of the factors of that size before TF is run; if we guess 10% of these factors are found by P-1, you would need 83 or so runs from 75 to 76 bits to expect to find one new factor.

Compare that time to 2 LL tests, and you should no longer wonder.


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