[Pw_forum] Computer cluster Parallel run:-Reg

[Bahadır salmankurt]

Dear Suresh

I faced the same problem. to deal with this, please uninstall mpi(if you
use it) and install older version. then configure and makeall espresso
again for this.

2015-08-11 16:58 GMT+03:00 Axel Kohlmeyer <akohlmey at gmail.com>:

> On Tue, Aug 11, 2015 at 7:01 AM, Suresh A <suresh2007pgp19 at gmail.com>
> wrote:
> > Respected Sir/Friends,
> >                     I have formed a PC beowulf cluster (X86_64 old PC's
> made
> > on 2007) and installed quantum espresso-5.2.0 in it. Now the cluster is
> > running very slowly than the single core i5 processor, DDR3 RAM with
> 1600MHZ
> > speed. The following is my observation in single core i5 processor and in
> > beowulf cluster for the titanium dioxide supercell of size 2x2x1. One
> more
> > thing is, in cluster every node has 2GB DDR2 RAM with speed 667 MHZ. for
> i5
> > processor 8GB with 1600 HZ.
> >
> > total cpu time spent upto now is    408.7 secs   (for  i5 CPU having
> > 1600MHZ)
> >
> > total cpu time spent upto now is    it is keepon running more than 1 hour
> > (for one single processor in PC cluster)
> >
> > total cpu time spent upto now is    1402 secs ( for -ni 10 -nk 10 in PC
> > cluster)
> >
> >
> >
> > Is this due to RAM speed, size or anything else?
>
> it is due to *everything*: clock rate, memory speed, memory
> architecture, processor architecture, processor cache size, disk
> caching efficiency, availability of SIMD instructions, compiler,
> libraries.
> the speed difference you quote seems quite normal for comparing a
> single core on current hardware versus 8 year old hardware.
>
> axel.
>
> >
> > Looking forward to your valuable suggestions
> >
> >                   With Regards,
> > A.Suresh,
> > Research Scholar,
> > Madurai Kamaraj University,
> > Madurai.
> >
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>
>
>
> --
> Dr. Axel Kohlmeyer  akohlmey at gmail.com  http://goo.gl/1wk0
> College of Science & Technology, Temple University, Philadelphia PA, USA
> International Centre for Theoretical Physics, Trieste. Italy.
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