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Message boards : General discussion : Enable Gerbicz correction in LLR2

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Joined: 25 Feb 20
Posts: 431
ID: 1241833
Credit: 238,722,572
RAC: 962,818
321 LLR Ruby: Earned 2,000,000 credits (2,092,823)Cullen LLR Amethyst: Earned 1,000,000 credits (1,169,946)ESP LLR Amethyst: Earned 1,000,000 credits (1,445,099)Generalized Cullen/Woodall LLR Amethyst: Earned 1,000,000 credits (1,148,593)PPS LLR Amethyst: Earned 1,000,000 credits (1,225,852)PSP LLR Amethyst: Earned 1,000,000 credits (1,248,861)SoB LLR Amethyst: Earned 1,000,000 credits (1,669,219)SR5 LLR Ruby: Earned 2,000,000 credits (2,065,004)SGS LLR Amethyst: Earned 1,000,000 credits (1,152,703)TRP LLR Ruby: Earned 2,000,000 credits (2,089,856)Woodall LLR Amethyst: Earned 1,000,000 credits (1,572,374)321 Sieve (suspended) Ruby: Earned 2,000,000 credits (2,107,153)PPS Sieve Amethyst: Earned 1,000,000 credits (1,045,010)AP 26/27 Ruby: Earned 2,000,000 credits (2,470,273)WW Double Silver: Earned 200,000,000 credits (207,744,000)GFN Turquoise: Earned 5,000,000 credits (7,489,336)PSA Amethyst: Earned 1,000,000 credits (1,022,470)
Message 147427 - Posted: 7 Jan 2021 | 20:00:32 UTC

I wanted to do some manual prime hunting and I'm not sure if Gerbicz is enabled by default or not. The help doesn't mention it at all, so I just had a look at PG's commandline and it has the option -oGerbicz=1. I added that but there is no confirmation the check is actually activated.

I'm using LLR2 from primegrid.com/download.

Also, no check files are created, but if I understood correctly, those are only required for doublechecking? The additional from Gerbicz works without them as well?
____________
1281979 * 2^485014 + 1 is prime ... no further hits up to: n = 4,400,000

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Discovered 1 mega primeFound 1 prime in the 2018 Tour de PrimesFound 1 prime in the 2019 Tour de PrimesFound 1 prime in the 2020 Tour de PrimesFound 1 prime in the 2021 Tour de Primes321 LLR Jade: Earned 10,000,000 credits (10,011,570)Cullen LLR Jade: Earned 10,000,000 credits (10,009,374)ESP LLR Jade: Earned 10,000,000 credits (10,009,221)Generalized Cullen/Woodall LLR Jade: Earned 10,000,000 credits (10,012,217)PPS LLR Jade: Earned 10,000,000 credits (16,271,644)PSP LLR Jade: Earned 10,000,000 credits (10,044,081)SoB LLR Jade: Earned 10,000,000 credits (10,064,750)SR5 LLR Jade: Earned 10,000,000 credits (10,002,051)SGS LLR Jade: Earned 10,000,000 credits (10,001,295)TRP LLR Jade: Earned 10,000,000 credits (10,002,411)Woodall LLR Jade: Earned 10,000,000 credits (10,013,921)321 Sieve (suspended) Sapphire: Earned 20,000,000 credits (20,004,228)Generalized Cullen/Woodall Sieve (suspended) Sapphire: Earned 20,000,000 credits (20,047,667)PPS Sieve Sapphire: Earned 20,000,000 credits (20,866,490)Sierpinski (ESP/PSP/SoB) Sieve (suspended) Sapphire: Earned 20,000,000 credits (20,043,271)TRP Sieve (suspended) Sapphire: Earned 20,000,000 credits (20,015,177)AP 26/27 Sapphire: Earned 20,000,000 credits (20,045,194)WW Jade: Earned 10,000,000 credits (19,704,000)GFN Emerald: Earned 50,000,000 credits (55,355,287)PSA Double Silver: Earned 200,000,000 credits (200,301,443)
Message 147436 - Posted: 8 Jan 2021 | 15:12:00 UTC - in response to Message 147427.
Last modified: 8 Jan 2021 | 15:13:25 UTC

I wanted to do some manual prime hunting and I'm not sure if Gerbicz is enabled by default or not. The help doesn't mention it at all, so I just had a look at PG's commandline and it has the option -oGerbicz=1. I added that but there is no confirmation the check is actually activated.

AFAIR in latest version it's enabled by default for Proth tests. For other types of tests you must use option above (of course you can just use this option always). The confirmation is a message "xxx checked" on status line (assuming you're running LLR with "-d" option for verbose output) and more parameters (L, M) on FFT status line. Non-Proth tests will also print "Gerbicz check requested, switching to PRP" message.

Note that Gerbicz test itself is not 100% bulletproof. First and few last iterations are not covered by Gerbicz check, only fast DC can catch errors at these places. But if your computer is stable and you've never seen a Gerbicz error in your testing, it's safe to consider that everything went fine.

Also, no check files are created, but if I understood correctly, those are only required for doublechecking?

Yes.

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321 LLR Ruby: Earned 2,000,000 credits (2,092,823)Cullen LLR Amethyst: Earned 1,000,000 credits (1,169,946)ESP LLR Amethyst: Earned 1,000,000 credits (1,445,099)Generalized Cullen/Woodall LLR Amethyst: Earned 1,000,000 credits (1,148,593)PPS LLR Amethyst: Earned 1,000,000 credits (1,225,852)PSP LLR Amethyst: Earned 1,000,000 credits (1,248,861)SoB LLR Amethyst: Earned 1,000,000 credits (1,669,219)SR5 LLR Ruby: Earned 2,000,000 credits (2,065,004)SGS LLR Amethyst: Earned 1,000,000 credits (1,152,703)TRP LLR Ruby: Earned 2,000,000 credits (2,089,856)Woodall LLR Amethyst: Earned 1,000,000 credits (1,572,374)321 Sieve (suspended) Ruby: Earned 2,000,000 credits (2,107,153)PPS Sieve Amethyst: Earned 1,000,000 credits (1,045,010)AP 26/27 Ruby: Earned 2,000,000 credits (2,470,273)WW Double Silver: Earned 200,000,000 credits (207,744,000)GFN Turquoise: Earned 5,000,000 credits (7,489,336)PSA Amethyst: Earned 1,000,000 credits (1,022,470)
Message 147652 - Posted: 18 Jan 2021 | 13:40:08 UTC - in response to Message 147436.
Last modified: 18 Jan 2021 | 13:42:07 UTC

Output looks like this:

1281979*2^881354+1 is not prime. Proth RES64: 5ED56E985D576B6A Time : 851.548 sec. Using zero-padded FFT length 96K, Pass1=128, Pass2=768, clm=4, a = 3, L2 = 246*224 1281979*2^881714+1, bit: 810000 / 881713 [91.86%], 771456 checked. Time per bit: 1.001 ms.


So it seems it's not enabled? I used llr2 -i tasks.pfgw -d as the command.
____________
1281979 * 2^485014 + 1 is prime ... no further hits up to: n = 4,400,000

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Discovered 1 mega primeFound 1 prime in the 2018 Tour de PrimesFound 1 prime in the 2019 Tour de PrimesFound 1 prime in the 2020 Tour de PrimesFound 1 prime in the 2021 Tour de Primes321 LLR Jade: Earned 10,000,000 credits (10,011,570)Cullen LLR Jade: Earned 10,000,000 credits (10,009,374)ESP LLR Jade: Earned 10,000,000 credits (10,009,221)Generalized Cullen/Woodall LLR Jade: Earned 10,000,000 credits (10,012,217)PPS LLR Jade: Earned 10,000,000 credits (16,271,644)PSP LLR Jade: Earned 10,000,000 credits (10,044,081)SoB LLR Jade: Earned 10,000,000 credits (10,064,750)SR5 LLR Jade: Earned 10,000,000 credits (10,002,051)SGS LLR Jade: Earned 10,000,000 credits (10,001,295)TRP LLR Jade: Earned 10,000,000 credits (10,002,411)Woodall LLR Jade: Earned 10,000,000 credits (10,013,921)321 Sieve (suspended) Sapphire: Earned 20,000,000 credits (20,004,228)Generalized Cullen/Woodall Sieve (suspended) Sapphire: Earned 20,000,000 credits (20,047,667)PPS Sieve Sapphire: Earned 20,000,000 credits (20,866,490)Sierpinski (ESP/PSP/SoB) Sieve (suspended) Sapphire: Earned 20,000,000 credits (20,043,271)TRP Sieve (suspended) Sapphire: Earned 20,000,000 credits (20,015,177)AP 26/27 Sapphire: Earned 20,000,000 credits (20,045,194)WW Jade: Earned 10,000,000 credits (19,704,000)GFN Emerald: Earned 50,000,000 credits (55,355,287)PSA Double Silver: Earned 200,000,000 credits (200,301,443)
Message 147656 - Posted: 18 Jan 2021 | 14:41:26 UTC - in response to Message 147652.

Output looks like this:

1281979*2^881354+1 is not prime. Proth RES64: 5ED56E985D576B6A Time : 851.548 sec. Using zero-padded FFT length 96K, Pass1=128, Pass2=768, clm=4, a = 3, L2 = 246*224 1281979*2^881714+1, bit: 810000 / 881713 [91.86%], 771456 checked. Time per bit: 1.001 ms.


So it seems it's not enabled? I used llr2 -i tasks.pfgw -d as the command.

It's enabled - 771456 checked - this is amount of iterations passed Gerbicz check.
As far as I remember latest LLR2 has Gerbicz check enabled by default for Proth tests because it's fully compatible and has almost zero cost in Proth. Other types of tests need an option - enabling Gerbicz will change their mode and/or residue.

Also ignore my previous words about "few last iterations are not covered by Gerbicz check". Pavel later corrected me that they are also protected.

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Joined: 25 Feb 20
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ID: 1241833
Credit: 238,722,572
RAC: 962,818
321 LLR Ruby: Earned 2,000,000 credits (2,092,823)Cullen LLR Amethyst: Earned 1,000,000 credits (1,169,946)ESP LLR Amethyst: Earned 1,000,000 credits (1,445,099)Generalized Cullen/Woodall LLR Amethyst: Earned 1,000,000 credits (1,148,593)PPS LLR Amethyst: Earned 1,000,000 credits (1,225,852)PSP LLR Amethyst: Earned 1,000,000 credits (1,248,861)SoB LLR Amethyst: Earned 1,000,000 credits (1,669,219)SR5 LLR Ruby: Earned 2,000,000 credits (2,065,004)SGS LLR Amethyst: Earned 1,000,000 credits (1,152,703)TRP LLR Ruby: Earned 2,000,000 credits (2,089,856)Woodall LLR Amethyst: Earned 1,000,000 credits (1,572,374)321 Sieve (suspended) Ruby: Earned 2,000,000 credits (2,107,153)PPS Sieve Amethyst: Earned 1,000,000 credits (1,045,010)AP 26/27 Ruby: Earned 2,000,000 credits (2,470,273)WW Double Silver: Earned 200,000,000 credits (207,744,000)GFN Turquoise: Earned 5,000,000 credits (7,489,336)PSA Amethyst: Earned 1,000,000 credits (1,022,470)
Message 147903 - Posted: 26 Jan 2021 | 18:16:44 UTC - in response to Message 147656.

Thanks, that's good to know.
____________
1281979 * 2^485014 + 1 is prime ... no further hits up to: n = 4,400,000

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Message boards : General discussion : Enable Gerbicz correction in LLR2

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