Hi All,

We have a parallel program running on a cluster. We recently found a case, which decreases the CPU usage and increase the run-time when increases Nodes. Below is the results table.

The particular run requires a lot of data communication between nodes.

Any thoughts about this phenomena? Or is there any way we can improve the CPU usage when using higher number of nodes?

Average CPU Usage (%)	Number of Nodes	Number of Threads/Node
100	1	8
92	2	8
50	3	8
40	4	8
35	5	8
30	6	8
25	7	8
20	8	8
20	8	4

Thanks!

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