Processes sharing cores on Ubuntu system
My coworkers and I share an 8-core server running Ubuntu for our batch processes.  I tend to run 4 processes at a time, each of which consumes 100% CPU per core when nothing else is running.  When a coworker runs his processes (typically about 4 at a time), his also get 100% per.  However, when both of us run ours (he always goes first), his still get 100% and mine seem to divide the remaining processing power and linger in the 10-40% range.  I even reniced his process to a lower value and it did not change.  What are the issues that may cause this?
Processes sharing cores on Ubuntu system
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My coworkers and I share an 8-core server running Ubuntu for our batch processes.  I tend to run 4 processes at a time, each of which consumes 100% CPU per core when nothing else is running.  When a coworker runs his processes (typically about 4 at a time), his also get 100% per.  However, when both of us run ours (he always goes first), his still get 100% and mine seem to divide the remaining processing power and linger in the 10-40% range.  I even reniced his process to a lower value and it did not change.  What are the issues that may cause this?