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Old 2008-03-26, 21:27   #24
gd_barnes's Avatar
May 2007
Kansas; USA

235448 Posts

Originally Posted by Mini-Geek View Post
27*2^100000-1 is not prime.  LLR Res64: B033EEE9274FF1F1  Time : 16.464 sec.
29*2^100000-1 is not prime.  LLR Res64: 7DF93B2FC5EF6077  Time : 16.583 sec.
27*2^100012-1 is not prime.  LLR Res64: 69F091E95935EE0E  Time : 16.588 sec.
27*2^100013-1 is not prime.  LLR Res64: CDAAE5C5F00C6FF5  Time : 16.586 sec.
31*2^100019-1 is not prime.  LLR Res64: 418D2ADE4901D642  Time : 16.610 sec.
31*2^100039-1 is not prime.  LLR Res64: FB1F60CAE7646CB3  Time : 16.599 sec.
31*2^100061-1 is not prime.  LLR Res64: 780E5645B0395BA2  Time : 16.591 sec.
31*2^100129-1 is not prime.  LLR Res64: CD3F553F0B3B61B4  Time : 16.618 sec.
27*2^100133-1 is not prime.  LLR Res64: 0E506AE171784315  Time : 16.612 sec.
27*2^259952-1 is not prime.  LLR Res64: A1E5B8F7FD1C606A  Time : 107.655 sec.
27*2^259973-1 is not prime.  LLR Res64: 5036B0FD0DFDBE74  Time : 107.636 sec.
31*2^259975-1 is not prime.  LLR Res64: D6A76B5B89DA91F8  Time : 107.720 sec.
27*2^260000-1 is not prime.  LLR Res64: B5D601E69D7F123F  Time : 107.740 sec.
Would these CPU timings help for a more accurate estimate, or something?
Well, we do know that Carlos machine will take about half the time that your machine will because the LLR timings are about half as much. The incremental analysis remains the same because the increment is still the same. The multiplier for time taken just changes. So he would take 4 and 7 days to do your two files.

But we do prefer not to have overclocked machines for this effort. But if Carlos has run an appropriate torture test and Anon is good with the test, then I'm OK with it. He knows more about how those specific torture tests work for various machines.

Edit: I could attempt to get down to the n=10 or n=1 level of the incremental analysis but the additional accuracy would not be worth it. Technically calculus needs to be used here. Unfortunately my basic calculus is not good enough so I generally resort to algebra and incremental analysis using formulas similar to compound interest calculations. Perhaps Axn1, Geoff, Robert, or even Mini-Geek here could chime in with some calculus that would give as exact of estimate as possible.

Exact CPU timings don't help for specific n's here with the way I did it because it would require an analysis of when FFTlen changes. Total CPU time spent for an n-range is what helps the most. But doing that analysis would give the most exact estimates.


Last fiddled with by gd_barnes on 2008-03-26 at 21:39
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