Dear sir,<br><br>You answer is quite helpful to me. Thank you very much. Actully, the speed of calculation for a large system is more <br>important for us. So I think the bandwidth is the key issue.<br><br>could I recognize the bandwidth you mentioned as the FSB (Front system bus) of the montherboard and the frequency of memory such as 800MHz or 1066 MHz and so on?<br>
<br>thank you for your reply<br><br>vega<br><br><div class="gmail_quote">On Wed, Mar 25, 2009 at 8:45 PM, Axel Kohlmeyer <span dir="ltr"><<a href="mailto:akohlmey@cmm.chem.upenn.edu">akohlmey@cmm.chem.upenn.edu</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;"><div class="im">On Wed, 2009-03-25 at 19:30 +0800, vega lew wrote:<br>
> Dear all,<br>
><br>
> Is there someone perform QE on intel I7 platform? Do you think<br>
> parallelzation QE could benefit from the QPI technology of intel I7<br>
> series very much?<br>
<br>
</div>the integrated memory controller and parallelization have very<br>
little connection directly. please don't "believe" in buzzwords.<br>
<br>
what _will_ help codes like Q-E in general is the greatly enhanced<br>
memory bandwidth, particularly the for larger systems. for smaller<br>
systems that mostly fit into the cache, the gains will be much smaller.<br>
the floating point unit of those cpus is essentially the same as in<br>
the current xeon processors.<br>
since the various tests posted on the list here demonstrated that<br>
(some of) Q-E's parallelization schemes are very much affected by<br>
insufficient memory bandwidth, there will be a gain. however, those<br>
CPUs will also have a different cache architecture, which may in<br>
turn chew up some of the benefits, particularly for smaller problems.<br>
<br>
cheers,<br>
axel.<br>
<div class="im"><br>
<br>
<br>
><br>
> vega<br>
><br>
> --<br>
> ==================================================================================<br>
> Vega Lew ( weijia liu)<br>
> PH.D Candidate in Chemical Engineering<br>
> State Key Laboratory of Materials-oriented Chemical Engineering<br>
> College of Chemistry and Chemical Engineering<br>
> Nanjing University of Technology, 210009, Nanjing, Jiangsu, China<br>
> ******************************************************************************************************************<br>
> Email: <a href="mailto:vegalew@gmail.com">vegalew@gmail.com</a><br>
> Office: Room A705, Technical Innovation Building, Xinmofan Road 5#,<br>
> Nanjing, Jiangsu, China<br>
> ******************************************************************************************************************<br>
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=======================================================================<br>
Axel Kohlmeyer <a href="mailto:akohlmey@cmm.chem.upenn.edu">akohlmey@cmm.chem.upenn.edu</a> <a href="http://www.cmm.upenn.edu" target="_blank">http://www.cmm.upenn.edu</a><br>
Center for Molecular Modeling -- University of Pennsylvania<br>
Department of Chemistry, 231 S.34th Street, Philadelphia, PA 19104-6323<br>
tel: 1-215-898-1582, fax: 1-215-573-6233, office-tel: 1-215-898-5425<br>
=======================================================================<br>
If you make something idiot-proof, the universe creates a better idiot.<br>
<br>
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</blockquote></div><br><br clear="all"><br>-- <br>==================================================================================<br>Vega Lew ( weijia liu)<br>PH.D Candidate in Chemical Engineering<br>State Key Laboratory of Materials-oriented Chemical Engineering<br>
College of Chemistry and Chemical Engineering<br>Nanjing University of Technology, 210009, Nanjing, Jiangsu, China<br>******************************************************************************************************************<br>
Email: <a href="mailto:vegalew@gmail.com">vegalew@gmail.com</a><br>Office: Room A705, Technical Innovation Building, Xinmofan Road 5#, Nanjing, Jiangsu, China <br>****************************************************************************************************************** <br>