[Cbc] How much better CBC performs when compiled with BLAS and LAPACK ?

[Haroldo Gambini Santos]

Thank you for your clarifications.  Yes, configure detects lapack and 
blas, so to build cbc without these components I added the 
--disable-lapack --disable-blas flags.


On 31-01-2015 06:57, John Forrest wrote:
> To add to Haroldo's comments.
>
> a) I think that the configure script can detect the existence of 
> lapack and blas - well it does on my computer.
>
> b) A dense factorization only really starts to help when the dense 
> part is of the order of 500.  Most "solvable" integer problems tend 
> not to fall in that category.
>
> c) However many difficult LP's do, with the dense part being of the 
> order of several thousand.  As the factorization effort is 
> proportional to n**3, a good set of blas makes a big difference. For 
> the latest set of simplex benchmarks by Hans Mittelmann, I asked him 
> to include the library "openblas", which made a significant difference.
>
> John Forrest
>
> On 31/01/15 04:03, Haroldo Gambini Santos wrote:
>> Hi all,
>>
>> Some years ago I asked this question.
>>
>> LAPACK and BLAS are fortran codes which can be compiled as Third-part 
>> components of CBC and may help in dense factorization operations.
>>
>> As part of my CBC benchmarking project I compared the CBC builds with 
>> and without these components.   Apparently there is a very small gain 
>> when this code is included:
>>
>> http://cbc.decom.ufop.br
>>
>> Cheers,
>>
>> Haroldo
>>
>
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-- 
==================================================
Haroldo Gambini Santos
D.Sc, Computer Science
Universidade Federal de Ouro Preto
http://www.decom.ufop.br/haroldo/