[Pw_forum] benchmark calculations for parallel PWSCF

[Nicola Marzari]

Dear Sahu,

I have mostly CP scaling data here, on small machines:
http://quasiamore.mit.edu/pmwiki/index.php?n=Main.CP90Timings

The bottom line is that provided that you use a recent MPI 
implementation, scaling is certainly very good using gigabit
ethernet up to 12 processors. We haven't tested anything larger.
Of course, gigabit ethernet is a slow connection.

I've seen tests done on the Cray XT4 that went up to 5000 processors, 
with excellent scaling. Some notes on hyperparallelization can be
found on the wiki
http://www.quantum-espresso.org/wiki/index.php/Running_on_parallel_machines

I do not have data for PWSCF - of course scaling on k-points or
NEB images would be perfect, but also on G-vectors should go
reasonably well with hundreds of CPUs. Maybe someone else has data
to share ?

				nicola


brsahu at physics.utexas.edu wrote:
> Dear PWSCF users,
> 
> Is it possibe to get a info on benchmark PWSCF SCF parallel  
> calculations (CPU time versus number of processors) for a particular  
> physical system on any computing machines (linux clusters, IBM (Power  
> series), SGI, HP etc.
> 
> Is it possible to share the numbers with me if you have such numbers?  
> I am aware that lot depends on what type of processors, what  
> communication channel, what libraries etc. But at this stage I am not  
> looking at a particular set of hardware/software set-up but only a  
> rough idea of how SCF parallel run scales with
> number of processors for a given system size
> 
> Bhagawan Sahu
> Microelectronics Research Center
> University of Texas at Austin
> 10100 Burnet Road, Bldg. 160
> MER 1.606H, Mail code R9900, TX 78758-4445
> e-mail: brsahu at physics.utexas.edu
> Phone: (512)-471-1344 FAX: (512)-471-8575
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Prof Nicola Marzari   Department of Materials Science and Engineering
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