Re: Performance with SSE2

>> Okay, I use 72x72 matrices and vectors of the size
72. So it might be
>> beneficial to use atlas-blas then!
> 
> Yes, unless your matrices are sparse.
"Standard" BLAS only support dense (and 
> sometimes packed, banded) matrices.

Hmm... most of them are actually sparse (compressed
matrix).

For future optimizations I better try these other proposed
methods out.
_______________________________________________
ublas mailing list
ublaslists.boost.org
htt
p://lists.boost.org/mailman/listinfo.cgi/ublas

Preben Hagh Strunge Holm wrote:

>>> Okay, I use 72x72 matrices and vectors of the
size 72. So it might be
>>> beneficial to use atlas-blas then!
>> 
>> Yes, unless your matrices are sparse.
"Standard" BLAS only support dense
>> (and sometimes packed, banded) matrices.
> 
> Hmm... most of them are actually sparse (compressed
matrix).
> 
> For future optimizations I better try these other
proposed methods out.

For size 72, the matrices would have to be *extremely*
sparse to see a
speedup over dense routines.  Sparse operations lose a lot
of efficiency on
mondern architectures from indirect pointer lookups, and
possibly poor
cache performance, whereas vectorized dense operations are
getting
relatively faster.  If you try some performance benchmarks
of BLAS vs
sparse, it would be interesting to see the results.

Cheers,
Ian


_______________________________________________
ublas mailing list
ublaslists.boost.org
htt
p://lists.boost.org/mailman/listinfo.cgi/ublas