[Wrf-users] WRF on BlueGene/L

[Andrew Porter]

Hello,
>
> We have been running WRF on our Intel based linux cluster and we wanted to
> try to run it on a BlueGene/L that we have access to. So, I just wanted to
> enquire as to whether anyone on this mailing list has had experience running WRF
> on this platform, and whether any open issues are present. The BlueGene/L that
> we have has 8096 processors.
>
I have run on a BG/P up to ~23K processors. Up to 8096 I was able to do 
this without problems (albeit playing with the node occupation because 
of the low memory per node). On large core counts I found the default 
netcdf IO layer of WRF becomes a huge bottleneck. Although I haven't 
tried it on the BG, I've found slides on t'internet that indicate that 
this is why the parallel netcdf layer was put into WRF.

God bless,

Andy.

-- 
Dr. Andrew Porter
Computational Scientist
Advanced Research Computing Group
Computational Science and Engineering Dept.
STFC Daresbury Laboratory
Keckwick Lane
Daresbury
WA4 4AD
Tel. : +44 (0)1925 603607
email: andrew.porter at stfc.ac.uk