Thread: Dodecaproths
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Old 2006-01-15, 10:23   #18
Kosmaj
 
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Nov 2003

2·1,811 Posts
Default R. Gerbicz

I noticed a large slow-down of dodeca.exe ver. 1.0 on a large range. Have a look. Case 1:
Code:
 
n=70, kmin=15, kmax=3000000000000000, version=1.0
Using the first 10 primes to reduce the size of the sieve array
Time=1968 sec.
Case 2:
Code:
n=70, kmin=3000000000000000, kmax=10000000000000000, version=1.0
Using the first 11 primes to reduce the size of the sieve array
   Status: 0.3 percentage of the project is complete. Time thusfar: 69 sec.
I stopped the second instance but 0.3% in 69 sec means 23000 sec for the range 7000T wide, while less than 2000sec were needed for a range 3000T wide. The only difference is the number of primes used (10 -> 11) so I guess it's related to magic_constant now set to 32000. Can you have a look and tell us how to avoid this kind of problems. Can you possibly set magic_constant dynamically based on input parameters (kmin and kmax) or enable "-x" on the cmd-line as you mentioned before for octo.exe. Thanks.

BTW, I checked all n=67-70 to 3000T but found no new DodecaProths.

Last fiddled with by Kosmaj on 2006-01-15 at 10:26
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