20070121, 05:08  #1 
Apprentice Crank
Mar 2006
11·41 Posts 
False primes!
During a hardware test, I was randomly testing some primes reported by PrimeGrid. Unfortunately, I found these to be composite:
1227950103*2^1950001 1949806593*2^1950001 This shouldn't have happened since all primes found by PrimeGrid were doublechecked. Since this was a random check, I haven't checked all the primes reported by PrimeGrid. However, those results warrant a complete doublecheck of all PrimeGrid primes 
20070121, 14:34  #2 
Oct 2005
Italy
3·113 Posts 
I remember that KEP had reported some false primes some time ago.

20070121, 15:10  #3 
Nov 2006
53_{16} Posts 
These are from the ancient (hehe) times when primes weren't doublechecked. The two are from users Finbar and The Bandit. I have reduced their prime number count.
[edit] I'll just add that if anyone wants to doublecheck PG primes, I can zip up and send the logs of all LLR tests. Last fiddled with by Rytis on 20070121 at 15:24 
20070121, 17:20  #4  
Quasi Admin Thing
May 2005
3AA_{16} Posts 
Quote:
So left is only to see how deep we have to go before we make it with our first prime to the top 5000 list Regards! 

20070121, 17:46  #5  
Sep 2002
Database er0rr
2^{2}×3×7×41 Posts 
From: http://www.formfactors.org/developer...12V_PS_1_1.pdf
Code:
Table 3. DC Output Voltage Regulation Output Range Min. Nom. Max. Unit (1) +12VDC ±5% +11.40 +12.00 +12.60 Volts +5VDC ±5% +4.75 +5.00 +5.25 Volts +3.3VDC ±5% +3.14 +3.30 +3.47 Volts 5VDC ±10% 4.50 5.00 5.50 Volts 12VDC ±10% 10.80 12.00 13.20 Volts +5VSB ±5% +4.75 +5.00 +5.25 Volts (1) At +12 VDC peak loading, regulation at the +12 VDC output can go to ± 10% Quote:


20070121, 18:36  #6  
Quasi Admin Thing
May 2005
2·7·67 Posts 
Quote:
Regards! 

20070121, 18:46  #7 
"Sander"
Oct 2002
52.345322,5.52471
29×41 Posts 
I think it's time for you to run a prime95 torture test for a day or two

20070121, 21:51  #8  
Quasi Admin Thing
May 2005
2×7×67 Posts 
Quote:
I'm by the way glad that you decided not to leave the TPS project anyway smh, you're very welcome to support the project, and I guess that you may have considered me hostile, as well as I considered you to be hostile towards Rytis, because we have no visiuals of one an other, but since this is a new year, I'll offer you my hand as a good guesture, and hope to see ud coexist on the message board, as well as various prime projects, as friends in stead of enemies. Life is simply to short to be enemies, and sadly not long enough, to accomplish all the prime goals that one can imagine... Kind regards! KEP 

20070121, 22:05  #9 
Dec 2006
Anchorage, Alaska
116_{8} Posts 
Sounds like you have some sort of mermory issue. How hot is your RAM getting when running the PRIME95 torture test? Can you hold it in your fingers, or is it too hot?
At the very least, I would suggest (if possible) to reduce your memory timings a little and see if that helps. 
20070121, 23:12  #10 
Apprentice Crank
Mar 2006
11×41 Posts 
I found another false prime by PrimeGrid:
1418514507*2^1950001 
20070122, 03:22  #11  
Quasi Admin Thing
May 2005
2×7×67 Posts 
Quote:
Regards! 

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