20211008, 00:10  #1 
Oct 2020
Terre Haute, IN
2×3^{2}×5 Posts 
How to help pare down P95 backlog
What job categories need the most help right now? The replacement for my gaming computer that overheated and died will be here in a couple days and I think I'd like to have that one help whittle down the pile of neglected jobs. Which category is most in need of workers?
Also, is it possible to run a duplicate PRP or other test on exponents that appear to be reserved but which haven't shown any progress in several years? I've been going through a number of 100Mdigit exponents on mersenne.ca and notice that several appear to have been in progress but no results have posted for at least a year or two. Last fiddled with by piforbreakfast on 20211008 at 00:49 
20211008, 02:33  #2  
6809 > 6502
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Aug 2003
101×103 Posts
2^{2}·41·61 Posts 
Doing DC's would be helpful.
Quote:


20211008, 03:35  #3 
Oct 2020
Terre Haute, IN
2·3^{2}·5 Posts 
Should I choose just doublechecking or doublechecking with proofs?
Last fiddled with by piforbreakfast on 20211008 at 04:29 
20211008, 20:25  #4 
"Oliver"
Sep 2017
Porta Westfalica, DE
1215_{8} Posts 
The difference in efficiency between them is small, lower than 3 % (estimated).
Doing a DC with a proof will give you an assingment for doing a PRP with proof on that number. This way, the DC is "done" in 99.9... % of cases. It is independet of the original run. Doing "normal" DC might yield to a triple check etc. being performed if the original and your calculations mismatch. But in the vast majority of cases, they will match and thus tell the performer of the original calculation that their run was sane. Personally, I am doing DC the "old fashioned" way. But: Do as you like. 
20211009, 12:57  #5 
Oct 2020
Terre Haute, IN
5A_{16} Posts 
For that matter, why are there still so many unverified LL tests in the system for exponents that have already been determined to not be prime? 57895237 was the last verified nonprime exponent listed on the front page as of a moment ago, but there are many exponents listed below that level, and not all of the unverified tests may be LL. Is P95 just ignoring these tests that are still in the system? Here's the link I was looking at:
https://www.mersenne.org/report_ll/?...dispdate=1&B1= 
20211009, 13:57  #6 
6809 > 6502
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Aug 2003
101×103 Posts
2^{2}×41×61 Posts 
If you click through to see the actual status of those numbers, say for instance: 53551349
you will see that some that don't have a matching LL, do have a PRP with cert. Thus they are double checked and we should move on. Last fiddled with by Uncwilly on 20211009 at 13:58 
20211009, 17:28  #7 
"TF79LL86GIMPS96gpu17"
Mar 2017
US midwest
5783_{10} Posts 
Many exponents with a single LL test will never get a second matching LL test. And should never.
Compute effort of LL DC is 1 primality test + ~0.040816... TC, QC, etc for 2% / test error rate; ~1.0408 cost. Compute effort of a PRP/proof as a DC substitute is ~1.005 primality test & only ~24 PPM error rate historically, so ~1.005024 cost; net savings ~3.56% by going with PRP DC/GEC/proof. (Overhead of Jacobi check for LL and GEC for PRP are comparable at ~0.20.3%, but GEC catches 99.99+% of errors while Jacobi catches 50.%.) Most LL single tests are several years old, longer than typical hardware useful lifetime, so the benefit of identifying flaky hardware by LLDC is hypothetical. 
20211009, 18:37  #8  
Aug 2002
North San Diego County
13×53 Posts 
Quote:
EDIT: In fact, one of your TC just let me know there is a machine that needs investigation. Last fiddled with by sdbardwick on 20211009 at 18:42 

20211009, 20:00  #9 
"TF79LL86GIMPS96gpu17"
Mar 2017
US midwest
13227_{8} Posts 

20211009, 20:10  #10 
If I May
"Chris Halsall"
Sep 2002
Barbados
37·269 Posts 

20211009, 21:29  #11 
Aug 2002
North San Diego County
689_{10} Posts 
Without the need for frequent monitoring of the individual computers?
Currently, I just check the completed assignment report occasionally, and see if there are any mismatches. Takes 5 seconds 3 times a week. PRP will complete successfully, albeit slowly, on computers with known issues. Last fiddled with by sdbardwick on 20211009 at 21:29 