Anders Logg wrote: > On Thu, Jul 17, 2008 at 11:19:09PM +0100, Garth N. Wells wrote: >> It's now easy to play with the sandbox programs in >> >> sandbox/mtl4/poisson_bench >> sandbox/mtl4/nse_bench >> >> All you need to do is set the environment variable MTL4_DIR to point to >> the MTL4 source, and then run scons in the relevant directory. > > Works fine here. > >> What's clear is that we should take a look at the efficiency of the >> sparsity computation. In particular, there are some virtual functions >> calls which can possibly be avoided, or at least minimised. Even when >> using MTL4 for general problems it will be necessary to compute some >> form of a sparsity pattern to estimate the number of nonzeros per row. >> >> It would be useful to use the same assembler for MTL4 as is used for >> other linear algebra backends to see what influence that has. > > I think it would be good to move the MTL4 interface into dolfin/la as > soon as possible. The missing functions can return an error until they > have been fixed. >
Agree. I'll add it today. > Then we should include MTL4 in the main assembly benchmark which is > > bench/fem/assembly/ > > If possible, we should figure out a way to run this benchmark > regularly (like we do with the buildbot) so we can check for > regressions. > >> The results for uninitialised MTL4 matrices are indeed impressive, as is >> the re-assembly time for Navier-Stokes. >> >> uBLAS and PETSc deliver almost identical performance for all tests. > > Here's what I get on my laptop (for n = 32). Do you get similar > results? > > Summary: MTL4 uBLAS > First matrix assembly 2.95 7.99 > Matrix re-assembly 2.51 3.58 > Vector assembly 2.38 2.49 > I get something like this. The timings for Poisson are generally closer than for Navier-Stokes. Garth > > > ------------------------------------------------------------------------ > > _______________________________________________ > DOLFIN-dev mailing list > [email protected] > http://www.fenics.org/mailman/listinfo/dolfin-dev _______________________________________________ DOLFIN-dev mailing list [email protected] http://www.fenics.org/mailman/listinfo/dolfin-dev
