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<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Arial",sans-serif">Dear cbc team:<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Arial",sans-serif"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Arial",sans-serif">I am a data scientist in Bosch, now I am working with cbc to solve a MILP problem. I have several questions regarding the running time of cbc need your support.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Arial",sans-serif"><o:p> </o:p></span></p>
<p class="MsoListParagraph" style="text-indent:-.25in;mso-list:l0 level1 lfo1"><![if !supportLists]><span style="font-size:10.0pt;font-family:"Arial",sans-serif"><span style="mso-list:Ignore">1.<span style="font:7.0pt "Times New Roman"">
</span></span></span><![endif]><span style="font-size:10.0pt;font-family:"Arial",sans-serif">When I run cbc solver on my computer(CPU 8cores + 32memory), I monitored my cpu performance and found the usage is about 35%. It seems that only 2 cores are working
in parallel.<o:p></o:p></span></p>
<p class="MsoListParagraph"><span style="font-size:10.0pt;font-family:"Arial",sans-serif">I also tried to set the thread by solver.options['threads'] =?(I am using pyomo to create to model), no matter how many threads I set, the running time has no significant
change.<o:p></o:p></span></p>
<p class="MsoListParagraph"><span style="font-size:10.0pt;font-family:"Arial",sans-serif"><o:p> </o:p></span></p>
<p class="MsoListParagraph"><span style="font-size:10.0pt;font-family:"Arial",sans-serif">So my first question is does cbc only support 2 cores computation in parallel?<o:p></o:p></span></p>
<p class="MsoListParagraph"><span style="font-size:10.0pt;font-family:"Arial",sans-serif"><o:p> </o:p></span></p>
<p class="MsoListParagraph" style="text-indent:-.25in;mso-list:l0 level1 lfo1"><![if !supportLists]><span style="font-size:10.0pt;font-family:"Arial",sans-serif"><span style="mso-list:Ignore">2.<span style="font:7.0pt "Times New Roman"">
</span></span></span><![endif]><span style="font-size:10.0pt;font-family:"Arial",sans-serif">I am using both cbc2.7.5 and cbc2.10.3, I found in some scenarios, cbc2.10.3 is even slower than the old version.<o:p></o:p></span></p>
<p class="MsoListParagraph"><span style="font-size:10.0pt;font-family:"Arial",sans-serif">e.g. for the attached model, the running time for 2.7.5 is
<b>220s</b>, for 2.10.3 is more than <b>10000s</b>. Could you help to check why and how to avoid that?<o:p></o:p></span></p>
<p class="MsoListParagraph"><span style="font-size:10.0pt;font-family:"Arial",sans-serif"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Arial",sans-serif">Thanks and looking forward to receiving your reply.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Arial",sans-serif"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Arial",sans-serif"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Arial",sans-serif;color:black">Best regards,
<br>
<br>
<b>Chenmin YU<br>
RBCD/MFE<br>
</b><br>
Tel. +86 510 8110-7322 | Mobil +86 018862117764 </span><span style="font-size:8.0pt;font-family:"Arial",sans-serif;color:black"><br>
<br>
</span><o:p></o:p></p>
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