pNetCDF and WRF

[John Michalakes]

It is GPFS. -John

> -----Original Message-----
> From: Robert Latham [mailto:robl at mcs.anl.gov]
> Sent: Monday, October 30, 2006 1:24 PM
> To: John Michalakes
> Cc: parallel-netcdf at mcs.anl.gov; Josh Hacker; Rich Loft
> Subject: Re: pNetCDF and WRF
> 
> 
> On Mon, Oct 30, 2006 at 12:18:41PM -0700, John Michalakes wrote:
> > Here are some preliminary results from the NCAR IBM Power5 system
> > (bluevista) comparing parallel NetCDF vs regular NetCDF output 
> in the WRF
> > model. This is for one of the standard WRF benchmark cases 
> (12km CONUS; see
> > http://www.mmm.ucar.edu/wrf/WG2/bench) where each write is 
> about 250 MB.  I
> > timed writes to a new NetCDF file and writes to an already 
> existing NetCDF
> > file separately.
> 
> Wow, I'm really surprised to see such a large penalty for creating the
> file.  What file system is this?  I see serial netcdf pays a small
> penalty, but it's more like 10% instead of PNetCDF's 50% penalty.  
> 
> > If anyone's intersted in obtaining this new version of WRF that uses
> > pNetCDF for your own testing, please let me know.
> 
> I sure am interested.  I might not be able to look at it very much
> until some time after supercomputing, but we would definitely like
> anohter workload we can use for our pnetcdf tuning efforts.
> 
> ==rob
> 
> -- 
> Rob Latham
> Mathematics and Computer Science Division    A215 0178 EA2D B059 8CDF
> Argonne National Lab, IL USA                 B29D F333 664A 4280 315B