Which BLAS to use with UMFPACK

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Jérémy

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Jul 4, 2013, 11:18:17 AM7/4/13
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 Hello,
 After some struggling I managed to install UMFPACK and link it to a code of decomposition in linear programming. In order to see the effect of the BLAS used by UMFPACK on computation time, I installed four versions of UMFPACK : one with no BLAS, one with the standard BLAS library, one with GotoBLAS2 and one with OpenBLAS.
 I then tested my code on benchmark involving 50 different matrices and I was very surprised to observe that the more the BLAS was refined and the longest it took to solve the linear systems. The results with no boas are about 20% better than with standard which are themselves about 30% better than with GotoBLAS and OpenBLAS (those two last blas provide very similar results which  is logical as OpenBlas is open is based on GotoBLAS).
 Has any of you observed such behavior ? Is there any possibility that a modification of some parameter could lead to results which are more consistent with the generally accepted assertion that OpenBlas should lead to better results ??
 Thanks !

Evgenii Rudnyi

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Jul 4, 2013, 3:14:04 PM7/4/13
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I would expect that UMPFACK with GotoBLAS should be faster. Yet, I have
no idea why you get the opposite effect.

Evgenii

On 04.07.2013 17:18 J�r�my said the following:
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