[Pw_forum] parallelization issue

[Paolo Giannozzi]

On Friday 15 October 2004 10:50, Giacomo Saielli wrote:

> I wonder if the comments of paragraph 7.4 of espresso manual v 2.1,
> parallelization issue of pw.x, apply also for the cp.x module.

they mostly apply to cp.x as well. Of course there is no k-kpoint 
parallelization in cp.x. I am not sure about the status of NEB image
parallelization in cp.x.

>     ecutwfc = 30.0,
>     ecutrho = 180.0,

25 and 100 Ry for C, N, H should be enough

> A test CPMD run with cp.x takes about 50 hours of total cpu 
> (16 procs on IBM SP4 at CINECA, all PE of the same node) 
> for 100 steps [...]. The question is if this numbers sounds
> correct to you, for this system size

1800 s/time step seems to me way too large for a system like 
yours. You can find reference CPU times on a SP3 here:
http://www.nest.sns.it/~giannozz/Papers/JCP_57.pdf
Divide by 2 or 3 to get an estimate for SP4.

Paolo 

-- 
Paolo Giannozzi             e-mail:  giannozz at nest.sns.it
Scuola Normale Superiore    Phone:   +39/050-509876, Fax:-563513 
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