Strategic Double Clicking

[Madpoo]

Originally Posted by sdbardwick

We matched. -As expected, given the different shifts noted by Madpoo.

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

[0PolarBearsHere]

Originally Posted by richs

My DC of 35939129 didn't match. Anyone like to TC it?

Matched your one.

[cuBerBruce]

Originally Posted by Madpoo

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:

exponent	worktodo
...
35795849	DoubleCheck=35795849,71,1
36056633	DoubleCheck=36056633,71,1
...

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]

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

[0PolarBearsHere]

Originally Posted by richs

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

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

[cuBerBruce]

Originally Posted by Madpoo

Here's more. From machines with at least a 3:1 bad:good ratio, using the "by calendar year" method:

exponent	Bad	Good	Unk	Sus	Solo	Mis	worktodo
...
51981047	7	2	11	8	11	8	DoubleCheck=51981047,73,1
...

I took this one.

[bloodIce]

Originally Posted by cuBerBruce

My residue did not match for M42003697.

Originally Posted by Madpoo

As weird as this sounds, that's exactly what I like to hear. Strange to be rooting for *mis* matched residues with these.

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]

Originally Posted by bloodIce

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...

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.

[Mark Rose]

Originally Posted by bloodIce

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...

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

[Prime95]

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

DoubleCheck=52210813,73,1
DoubleCheck=55443329,73,1
DoubleCheck=55894291,73,1
DoubleCheck=56542063,73,1
DoubleCheck=56699557,73,1
DoubleCheck=57740621,73,1

[VBCurtis]

Originally Posted by bloodIce

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...

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.