[FLASH-USERS] Improving the load balancing in FLASH

[Anshu Dubey]

This was considered several years ago. Then Mike Zingale and Jonathan
Dursi proved that the computational savings from coarse blocks having
a coarse time step are too insignificant to be worth pursuing. This is
because the computational time in the finer blocks completely
dominates that in coarser blocks for the same area of computational
domain. I believe that study appeared in some proceedings, if you are
interested I can dig up the reference.

Anshu

On Tue, Sep 8, 2009 at 4:17 AM, Ross Parkin<phy1erp at leeds.ac.uk> wrote:
> Hello,
>
> I've been thinking about the load balancing method used in FLASH. The
> timestep used by the hydro units is the same on all refinement levels and so
> blocks are essentially distributed by paramesh so that all processors have
> the roughly the smae number of blocks. Has anyone tried modifying FLASH so
> that each refinement level has its own timestep? To do this properly you
> would need to modify how PARAMESH distributes blocks amongst processors,
> taking account of the relative work done by each block on each refinement
> level, i.e. a block on a finer refinement level may need to do twice as many
> hydro loops before its simulation time equals that of a coarser block.
>
> Any ideas guys?
>
> Cheers,
>
> Ross Parkin
>