PRP versus LL first tests for Prime95 / impact on GPU factoring

[Prime95]

Originally Posted by wfgarnett3

When you go to Test-->Status for my PRP test for my M85XXXXXX exponent, is it my imagination that the probability for "The chance that your exponent you are testing will yield a Mersenne prime is about 1 in ......." is significantly worse then when I did a first time LL in the previous version of the software?

If I am not imagining things, why is it?

What does the worktodo.txt entry look like?

[axn]

Originally Posted by wfgarnett3

If in both cases they are first time tests why is the probability stated in Prime95 of the exponent being a Mersenne prime significantly worse with PRP than LL?

They shouldn't. The type of test doesn't affect the probability; only the size of number (i.e. exponent) and amount of factorizartion (TF + P-1) does. It would be good if you can put some screenshots of the probability.

[wfgarnett3]

The exponent is being PRP tested on my home desktop computer with Prime95

Here at work I just downloaded Prime95 and copied the worktodo info from mersenne.org and Prime95 is reporting a correct probability for the first time PRP test. (image1 attached).
that is similar to prior LL first time probabilities.

When I get home from work later today I will attach the screenshot from Prime95 of my home desktop machine and you will see then Prime95 at home is reporting an incorrect probability for the first time PRP test that is significantly worse than the first time PRP test on my work laptop on the same exact exponent.

[Prime95]

Make sure worktodo.txt does not read "PRPDC=....."

[wfgarnett3]

Attached is image2 which shows this home computer was indeed reporting a worse, incorrect probability for this first time PRP test of the exponent.

The worktodo.txt on this home computer is the below:

PRP=0A5CF58B6C3666AC9FE2A5E244054E24,1,2,85375753,-1

while when I log into mersenne.org it shows the worktodo text to copy as the below (which I used on my work laptop for image1):

PRP=0A5CF58B6C3666AC9FE2A5E244054E24,1,2,85375753,-1,76,0,3,

Is the "factored to 76 bit" missing in worktodo.txt the reason for the incorrect first time test probability?

If so, what is wrong with Prime95/PrimeNet, as Prime95 automatically got this assignment on its own but failed to put the factored 76 bit pieces into the PRP worktodo on its own like it used to when I used the previous version software for LL testing?

[Prime95]

Originally Posted by wfgarnett3

Is the "factored to 76 bit" missing in worktodo.txt the reason for the incorrect first time test probability?

Yes, prime95 assumed no TF had been done.

If so, what is wrong with Prime95/PrimeNet, as Prime95 automatically got this assignment on its own but failed to put the factored 76 bit pieces into the PRP worktodo on its own like it used to when I used the previous version software for LL testing?

Older versions of prime95 wasn't smart enough to write that info to worktodo.txt

[wfgarnett3]

But it is the newer software that failed to write the info to worktodo.txt

The older version from 2018 always wrote the factored info in the worktodo.txt when communicating with PrimeNet for LL testing on my home desktop.

This new version on my home desktop (placed in its own folder directory in Windows 10) didn't write the info when it communicated with PrimeNet to get the PRP assignment. Image2 from my current PRP first time test is from your latest version of Prime95 from your homepage that you released this month. Prime95 left out the factoring info by itself for this new assignment where the 2018 version always had the info in for prior assignments. That's why I wondered why the probability was off -- the factored info is missing.

Is this a PrimeNet issue or Prime95 issue?

[Prime95]

Originally Posted by wfgarnett3

-- the factored info is missing.

Is this a PrimeNet issue or Prime95 issue?

This is a prime95 issue (old and new versions). Prime95 is only writing the how-far-factored data if P-1 is required.

[wfgarnett3]

George,

Do you mean P-1 is required only for LL test and not PRP?

My 2nd PRP likewise has missing bit information while if Iog into mersenne.org it shows the 76 bit factored information (and P-1 was already done).

In a future version you might want to fix this since PRP testing is not showing the true probability like it does with LL testing (i.e. it shows a worse probability for PRP that no factoring has taken place which isn't true...).

William

[Prime95]

P-1 is recommended for both LL and PRP.

[wfgarnett3]

OK then this newer version of Prime95 / PrimeNet is failing to properly include the right info in the worktodo.txt for me -- I won't worry too much about it since it only affects stated probability not actual testing...