<div class="gmail_quote">On Fri, Mar 16, 2012 at 14:52, <span dir="ltr"><<a href="mailto:Nan.Jia@dartmouth.edu">Nan.Jia@dartmouth.edu</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
Dear PETSc Group,<br>
I am tuning the efficiency of my PETSc code for a while, but get very little progress. So can anyone help me to analysis the log? Any suggestions will be appreciated.<br>
<br>
My problem is time dependent. At every time step, two about 6000 by 6000 sparse matrices need to be solved, which come from a Poisson equation. I use both sequential and parallel AIJ format to store matrices, but the performances are both not very good.<br>
</blockquote><div><br></div><div>1. You need to heed the huge warning</div><div><font face="'courier new', monospace"><br></font></div><div><div><font face="'courier new', monospace"> ##########################################################</font></div>
<div><font face="'courier new', monospace"> # #</font></div><div><font face="'courier new', monospace"> # WARNING!!! #</font></div>
<div><font face="'courier new', monospace"> # #</font></div><div><font face="'courier new', monospace"> # This code was compiled with a debugging option, #</font></div>
<div><font face="'courier new', monospace"> # To get timing results run config/configure.py #</font></div><div><font face="'courier new', monospace"> # using --with-debugging=no, the performance will #</font></div>
<div><font face="'courier new', monospace"> # be generally two or three times faster. #</font></div><div><font face="'courier new', monospace"> # #</font></div>
<div><font face="'courier new', monospace"> ##########################################################</font></div></div><div><br></div><div><br></div><div><br></div><div>2. You only spend 18 of 880 seconds in the solver. What do you want?</div>
<div><br></div>3. The problem is too small to get significant parallel speedup.</div><div class="gmail_quote"><br></div><div class="gmail_quote"><a href="http://www.mcs.anl.gov/petsc/documentation/faq.html#slowerparallel">http://www.mcs.anl.gov/petsc/documentation/faq.html#slowerparallel</a><br>
</div>