dolfin team mailing list archive

[Johan Hake <hake@xxxxxxxxx>]

On Monday 21 September 2009 21:37:03 Anders Logg wrote:
> Johan and I have set up a benchmark for parallel speedup in
> 
>   bench/fem/speedup
> 
> Here are some preliminary results:
> 
>   Speedup  |  Assemble  Assemble + solve
>   --------------------------------------
>   1        |         1                 1
>   2        |    1.4351            4.0785
>   4        |    2.3763            6.9076
>   8        |    3.7458            9.4648
>   16       |    6.3143            19.369
>   32       |    7.6207            33.699
> 
> These numbers look a bit strange, especially the superlinear speedup
> for assemble + solve. There might be a bug somewhere in the benchmark
> code.
> 
> Anyway, we have some preliminary results that at least show some kind
> of speedup.
> 
> It would be interesting to hear some comments on what kind of numbers
> we should expect to get from Matt and others.
> 
> The benchmark is for assembling and solving Poisson on a 64 x 64 x 64
> mesh using PETSc/MUMPS. Partitioning time is not included in the
> numbers.

What solver is used when the number of processors is 1? If this is different 
from MUMPS, we will have the performance difference between the two solvers 
included in the speedup bump when going from 1 -> 2 processors.

Johan

> --
> Anders
>