<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=Windows-1252">
</head>
<body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;">
<div style="color: rgb(0, 0, 0); font-family: Calibri, sans-serif; font-size: 14px;">
Hi Vijay & <span style="white-space: pre-wrap; widows: 1;">Iulian,</span></div>
<div style="color: rgb(0, 0, 0); font-family: Calibri, sans-serif; font-size: 14px;">
<span style="white-space: pre-wrap; widows: 1;"><br>
</span></div>
<div style="widows: auto;"><span style="widows: 1;"><font face="Calibri,sans-serif"><span style="white-space: pre-wrap;">Hope you are doing well!
</span></font></span><font face="Calibri,sans-serif"><span style="white-space: pre-wrap;">I have a question regarding some strange behavior we’re seeing with the
</span></font>DMMoabLoadFromFile() function…</div>
<div style="widows: auto;"><br>
</div>
<div style="widows: auto;">After doing some recent profiling of our MOAB-based finite element code, we noticed that we are spending a disproportionate amount of CPU time within the DMMoabLoadFromFile() function, which gets slower / remains constant as we increase
the number of processors. We also recently attempted a scalability test with ~30M FEM nodes on 500 processors which hung in DMMoabLoadFromFile() for about 45 minutes before we killed the job. We then re-ran the test on one processor and it made it through
successfully in several seconds. </div>
<div style="widows: auto;"><br>
</div>
<div style="widows: auto;">To reproduce the problem we’re seeing, we wrote a test case (attached here) that simply loads a smaller mesh with approximately 16K nodes and prints the run time. When I run the code on an increasing number of processors, I get something
like:</div>
<div><span style="widows: 1;"><font face="Calibri,sans-serif"><span style="white-space: pre-wrap;"><br>
</span></font></span></div>
<div style="color: rgb(0, 0, 0); font-family: Calibri, sans-serif; font-size: 14px;">
NP=1: Time to read file: 0.0416839 [sec.]</div>
<div style="color: rgb(0, 0, 0); font-family: Calibri, sans-serif; font-size: 14px;">
NP=2: Time to read file: 1.42497 [sec.]</div>
<div style="color: rgb(0, 0, 0); font-family: Calibri, sans-serif; font-size: 14px;">
NP=4: Time to read file: 1.13678 [sec.]</div>
<div style="color: rgb(0, 0, 0); font-family: Calibri, sans-serif; font-size: 14px;">
NP=8: Time to read file: 1.0475 [sec.]</div>
<div style="color: rgb(0, 0, 0); font-family: Calibri, sans-serif; font-size: 14px;">
…</div>
<div style="color: rgb(0, 0, 0); font-family: Calibri, sans-serif; font-size: 14px;">
<br>
</div>
<div style="color: rgb(0, 0, 0); font-family: Calibri, sans-serif; font-size: 14px;">
If it is relevant/helpful – we are using the mbpart tool to partition the mesh. Do you have any ideas why we are not seeing scalability here? Any thoughts/tips would be appreciated! Let me know if you would like any more information. </div>
<div style="color: rgb(0, 0, 0); font-family: Calibri, sans-serif; font-size: 14px;">
<br>
</div>
<div style="color: rgb(0, 0, 0); font-family: Calibri, sans-serif; font-size: 14px;">
Thanks,</div>
<div style="color: rgb(0, 0, 0); font-family: Calibri, sans-serif; font-size: 14px;">
Jim</div>
<div style="color: rgb(0, 0, 0); font-family: Calibri, sans-serif; font-size: 14px;">
<br>
</div>
<div style="color: rgb(0, 0, 0); font-family: Calibri, sans-serif; font-size: 14px;">
<div><br>
</div>
<div><br>
</div>
</div>
</body>
</html>