dolfin team mailing list archive

["Dag Lindbo" <dag@xxxxxxxxxx>]

Hello!

In light of the long and interesting discussion we had a while ago about
assembler performance I decided to try to squeeze more out of the uBlas
backend. This was not very successful.

However, I've been following the development of MTL4
(http://www.osl.iu.edu/research/mtl/mtl4/) with a keen eye on the
interesting insertion scheme they provide. I implemented a backend --
without sparsity pattern computation -- for the dolfin assembler and here
are some first benchmarks results:

Incomp Navier Stokes on 50x50x50 unit cube

MTL --------------------------------------------------------
assembly time: 8.510000
reassembly time: 6.750000
vecor assembly time: 6.070000

memory: 230 mb

UBLAS ------------------------------------------------------
assembly time: 23.030000
reassembly time: 12.140000
vector assembly time: 6.030000

memory: 642 mb

Poisson on 2000x2000 unit square

MTL --------------------------------------------------------
assembly time: 9.520000
reassembly time: 6.650000
assembly time: 4.730000
vector linear solve: 0.000000

memory: 452 mb

UBLAS ------------------------------------------------------
assembly time: 15.400000
reassembly time: 7.520000
vector assembly time: 5.020000

memory: 1169 mb

Conclusions? MTL is more than twice as fast and allocates less than half
the memory (since there is no sparsity pattern computation) across a set
of forms I've tested.

The code is not perfectly done yet, but I'd still be happy to share it
with whoever wants to mess around with it.

Cheers!

/Dag