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<DIV><FONT face="Bookman Old Style">Thanks. I will read it:-)</FONT></DIV>
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<DIV style="FONT: 9pt 宋体">----- Original Message ----- </DIV>
<DIV style="BACKGROUND: #e4e4e4; FONT: 9pt 宋体; font-color: black"><B>From:</B>
<A title=knepley@gmail.com href="mailto:knepley@gmail.com">Matthew Knepley</A>
</DIV>
<DIV style="FONT: 9pt 宋体"><B>To:</B> <A title=petsc-users@mcs.anl.gov
href="mailto:petsc-users@mcs.anl.gov">petsc-users@mcs.anl.gov</A> </DIV>
<DIV style="FONT: 9pt 宋体"><B>Sent:</B> Thursday, October 26, 2006 8:53
PM</DIV>
<DIV style="FONT: 9pt 宋体"><B>Subject:</B> Re: how many processes is
better?</DIV>
<DIV><BR></DIV>On 10/26/06, <B class=gmail_sendername>Yixun Liu</B> <<A
href="mailto:yxliu@fudan.edu.cn">yxliu@fudan.edu.cn</A>> wrote:
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<DIV><FONT face="Bookman Old Style">Hi,</FONT></DIV>
<DIV><FONT face="Bookman Old Style">I want to know how many processes is
better. My computer is dual processors PC with superthread. According to the
exampe ex2 I set the problem domain to 800*200. I set the number of
processes to 1,2,4,10 respecively and the runtime is 26, 19, 18, 15
respectively. How many processes is better. In my opinion 4(2processors *
2superthreads) is better based on my computer, but why 10 ran more
quickly?</FONT></DIV></DIV></BLOCKQUOTE>
<DIV><BR>Again, this question is about gneric theory of parallel processing,
and really has not answer<BR>as you pose it. I suggest the book "Parallel
Computing" by Grama, et. al. <BR><BR> Matt<BR></DIV><BR>
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<DIV><FONT face="Bookman Old Style">Best, </FONT></DIV>
<DIV><FONT face="Bookman Old Style"></FONT> </DIV>
<DIV><FONT
face="Bookman Old Style">Yixun</FONT></DIV></DIV></BLOCKQUOTE></DIV><BR><BR
clear=all><BR>-- <BR>"Failure has a thousand explanations. Success doesn't
need one" -- Sir Alec Guiness </BLOCKQUOTE></BODY></HTML>