20150503, 18:50  #1 
Dec 2002
5·167 Posts 
Require P1 and other factoring work to be done on reliable machines
I've been doing some extra factoring in the 12M and 10M range lately using mfaktc. I've found a few P1 errors in the 10M range and many in the 12M range. This leaves me to believe one or some machines have done and may still do P1 factoring that are highly unreliable. This causes others to have to do a whole lot more work which is completely unnecessary. Can and should we demand P1 machines to do reliability tests that include heavy memory integrity checks?

20150504, 05:41  #2  
1976 Toyota Corona years forever!
"Wayne"
Nov 2006
Saskatchewan, Canada
11572_{8} Posts 
Quote:
Or invalid factors submitted....I don't think PrimeNet allows this...that is they are all verified as valid factors. 

20150504, 11:32  #3 
Dec 2002
5·167 Posts 

20150504, 14:36  #4 
Nov 2003
2^{2}×5×373 Posts 

20150504, 20:31  #5  
Dec 2002
5×167 Posts 
Quote:


20150504, 20:40  #6  
Serpentine Vermin Jar
Jul 2014
3324_{10} Posts 
Quote:
I didn't go through the exercise of seeing which previous P1 runs were actually done prior to the LL test, or whether or not it *should have* found the factor that was eventually found. So out of context like that, the #s above are kind of meaningless in terms of answering the question (whether sincere or not). 

20150504, 21:13  #7  
Nov 2003
2^{2}×5×373 Posts 
Quote:


20150504, 21:17  #8 
If I May
"Chris Halsall"
Sep 2002
Barbados
10184_{10} Posts 

20150504, 21:18  #9  
Nov 2003
2^{2}·5·373 Posts 
It was not.
Quote:
Are these instances where both TD and P1 FAILED, prior to running LL, even though P1 later found a factor?? People also need to understand. For P1 to succeed when (say) P1 is divisible by a prime to a degree higher than 1, the software must include the higher power in the smoothness bound. Last fiddled with by R.D. Silverman on 20150504 at 21:19 Reason: missed quotes 

20150504, 21:31  #10  
Serpentine Vermin Jar
Jul 2014
CFC_{16} Posts 
Quote:
I won't lose sleep over it those. Missing a factor that *should have* been found is inconvenient since it results in one or more LL checks (depending on if a factor is found later), but it's still just a mere inconvenience. Still, if someone wants to go through and doublecheck previous P1 runs by a computer that may have been flaky, more power to them. It has happened, where a machine doing factoring work of some kind simply missed things. Whether it was caught before or after an LL test is the part I'm not sure we'd always have an answer to. I spot checked a handful of exponents where:
From my spot checks, everything looked okay, but I had to artificially limit myself to LL runs where the date was known. It was a pretty small subset of around 100 exponents, and for some a successful factoring job the first time around would have only saved a doublecheck since the firsttime LL test had already been done. My understanding of P1 and probabilities of finding a factor are limited though so it may not have been obvious to me if the factor that was found would have actually been found by a previous check. My guess on the spot checks were "no" because the bounds were kind of small on the first run. But honestly I spent maybe 10 minutes checking and then moved on so take that for whatever it's worth. 

20150504, 21:47  #11 
Nov 2003
7460_{10} Posts 

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