#2008: NaNs when running static tov on >40 cores ------------------------------------+--------------------------------------- Reporter: allgwy001@… | Owner: knarf Type: defect | Status: assigned Priority: unset | Milestone: Component: Other | Version: ET_2016_05 Resolution: | Keywords: ------------------------------------+---------------------------------------
Comment (by allgwy001@…):
Here are some comments I received from the person who compiled the Einstein Toolkit on the cluster I'm using. He ran tests with the static tov star parameter file I attached, and sent me the following:
"The times follow a standard MPI reduction pattern. Out beyond 24 cores the code/data does not scale well and latency from message passing starts to increase rather than reduce run times. Some increases in ppn values increase the run times; this may be due to how data objects are handled in the code. There is also some fluctuation in the data runs which can only be caused by the software as I ran all tests on node 607 while no one else was using it."
He suggested that if I want to do runs on more than 20 cores (which I do), then I should ask for advice from people more familiar with the Einstein Toolkit.