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Old 2020-12-19, 01:44   #45
diep
 
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Sep 2006
The Netherlands

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Quote:
Originally Posted by VBCurtis View Post
You really shouldn't be trying to defeat the LLR decision to use the bigger FFT. A silent rounding error, while unlikely, is possible. I'd rather do one test at 25k seconds than a set of double-checks at 18k sec each because the results aren't as trustworthy.
The rounding error seems to sometimes happen when the FFT length is not far from taking the next increase. As i'm not so long inside the next increase i feel pretty safe there.

So for example the first problem i got here was at

proces 1 : 32767*2^4150241-1 is not prime. LLR Res64: 65B3BF50D94E6A58 Time : 17524.087 sec.
Iter: 647351/4152080, ERROR: ROUND OFF (0.4375) > 0.4
Continuing from last save file.

So at 4.15M which is close to the next increase at 4.16M

proces 2:
32767*2^4157121-1 is not prime. LLR Res64: 1E3B0D7CC9B9EE93 Time : 15966.340 sec.
Iter: 1614226/4158992, ERROR: ROUND OFF (0.4375) > 0.4
Continuing from last save file.
Resuming LLR test of 32767*2^4158993-1 at iteration 1424769 [34.25%]
32767*2^4158993-1 is not prime. LLR Res64: 7A567993821E36DA Time : 17787.690 sec.

Also close to 4.16M

proces 3:
32767*2^4163073-1 is not prime. LLR Res64: AEF3BE86379E13DE Time : 17503.145 sec.
Iter: 892365/4163840, ERROR: ROUND OFF (0.4375) > 0.4
Continuing from last save file.
Resuming LLR test of 32767*2^4163841-1 at iteration 648321 [15.57%]
Disregard last error. Result is reproducible and thus not a hardware problem.
For added safety, redoing iteration using a slower, more reliable method.

That's even closer to the jump at 4.168M

and first error at proces 4:
32767*2^4159313-1 is not prime. LLR Res64: 17ECE1E45391CA65 Time : 17019.632 sec.
Iter: 98335/4161488, ERROR: ROUND OFF (0.40625) > 0.4
Continuing from last save file.
Resuming LLR test of 32767*2^4161489-1 at iteration 2 [0.00%]
Disregard last error. Result is reproducible and thus not a hardware problem.
For added safety, redoing iteration using a slower, more reliable method.
Continuing from last save file.
Resuming LLR test of 32767*2^4161489-1 at iteration 98335 [2.36%]
32767*2^4161489-1 is not prime. LLR Res64: F365133D3BB48CDF Time : 21613.205 sec.

Also close to 4.16M.
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