<html>
<head>
<style><!--
.hmmessage P
{
margin:0px;
padding:0px
}
body.hmmessage
{
font-size: 10pt;
font-family:Tahoma
}
--></style></head>
<body class='hmmessage'><div dir='ltr'>
Professor Giannozzi,<div><br></div><div>Thanks for the reply. The CPU time is 1 hr 26 min (2hrs 2 min normal time) for the scf calculation on the nodes (3 of them). If I have 42 atoms then this is equivalent to almost 8 days CPU time or 10 days normal time. Four days have passed and I am still in representation 6 out of 126 which i guess is not the normal situation...Can anything be done (or checked) in this case?</div><div><br></div><div>Regards</div><div><br></div><div><br></div><div>Elie</div><br><div><div id="SkyDrivePlaceholder"></div>> CC: pw_forum@pwscf.org<br>> From: giannozz@democritos.it<br>> Subject: Re: [Pw_forum] parallel computation too slow<br>> Date: Fri, 16 Mar 2012 21:48:15 +0100<br>> To: elie.moujaes@hotmail.co.uk<br>> <br>> <br>> On Mar 16, 2012, at 19:14 , Elie M wrote:<br>> <br>> > I am running phonon calculations for a supercell of 60 atoms at the <br>> > gamma point [...]<br>> > What could the possible causes of this slowness be? Is it something <br>> > to do with the<br>> > nodes or with phonon calculations in general? Is there a way to check?<br>> <br>> ><br>> <br>> a phonon calculation for N atoms requires a CPU time of the order of <br>> 3N the time of<br>> the correspoding scf calculation. Does yours? if it does, there is <br>> nothing that can be<br>> done.<br>> <br>> P.<br>> ---<br>> Paolo Giannozzi, Dept of Chemistry&Physics&Environment,<br>> Univ. Udine, via delle Scienze 208, 33100 Udine, Italy<br>> Phone +39-0432-558216, fax +39-0432-558222<br>> <br>> <br>> <br>> <br></div> </div></body>
</html>