<html><head><meta http-equiv="Content-Type" content="text/html; charset=us-ascii"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class="">It depends on the solver used. What solver are you using?<br class=""><div><br class=""><blockquote type="cite" class=""><div class="">On Jul 11, 2022, at 5:33 PM, Ce Qin <<a href="mailto:qince168@gmail.com" class="">qince168@gmail.com</a>> wrote:</div><br class="Apple-interchange-newline"><div class=""><div dir="ltr" class=""><div dir="ltr" class=""><div dir="ltr" class="">Dear all,<div class=""><br class=""></div><div class="">I want to analyze the strong scaling of our in-house FEM code.</div><div class="">The test problem has about 20M DoFs. I ran the problem using</div><div class="">various settings. The speedups for the assembly and solving</div><div class="">procedures are as follows:</div><div class=""><div class=""><font face="monospace" class=""> Assembly Solving</font></div><div class=""><font face="monospace" class="">NProcessors NNodes CoresPerNode </font></div><div class=""><font face="monospace" class="">1 1 1 1.0 1.0</font></div><div class=""><font face="monospace" class="">2 1 2 1.995246 1.898756</font></div><div class=""><font face="monospace" class=""> 2 1 2.121401 2.436149</font></div><div class=""><font face="monospace" class="">4 1 4 4.658187 6.004539</font></div><div class=""><font face="monospace" class=""> 2 2 4.666667 5.942085</font></div><div class=""><font face="monospace" class=""> 4 1 4.65272 6.101214</font></div><div class=""><font face="monospace" class="">8 2 4 9.380985 16.581135</font></div><div class=""><font face="monospace" class=""> 4 2 9.308575 17.258891</font></div><div class=""><font face="monospace" class=""> 8 1 9.314449 17.380612</font></div><div class=""><font face="monospace" class="">16 2 8 18.575953 34.483058</font></div><div class=""><font face="monospace" class=""> 4 4 18.745129 34.854409</font></div><div class=""><font face="monospace" class=""> 8 2 18.828393 36.45509</font></div><div class=""><font face="monospace" class="">32 4 8 37.140626 70.175879</font></div><div class=""><font face="monospace" class=""> 8 4 37.166421 71.533865</font></div></div><div class=""><font face="monospace" class=""><br class=""></font></div><div class=""><font face="arial, sans-serif" class="">I don't quite understand this result. Why we can achieve</font><font face="arial, sans-serif" class=""> a speedup of</font></div><div class=""><font face="arial, sans-serif" class="">about </font><span style="font-family:arial,sans-serif" class="">70+ using 32 processors? Could you please help me explain this?</span></div><div class=""><br class=""></div><div class=""><font face="arial, sans-serif" class="">Thank you in advance.</font></div><div class=""><font face="arial, sans-serif" class=""><br class=""></font></div><div class=""><font face="arial, sans-serif" class="">Best,</font></div><div class=""><font face="arial, sans-serif" class="">Ce</font></div><div class=""><font face="monospace" class=""><br class=""></font></div><div class=""><font face="monospace" class=""><br class=""></font></div></div></div></div>
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