Scheduling influences on simulation outcomes?

In HPC land you often have a slightly different way of thinking.

As supercomputers are expensive you are often thinking in terms of The Computer rather than a computer. Porting to a different machine is usually a significant task, and to maintain maximum performance you are often using lots of non-portable tricks that will need adjusting. Things like memory size, core count, or core binding are often configured relatively statically.

Because of this a supercomputer port is usually accompanied by an evaluation phase where subject matter experts look at the outputs and decide if it is close enough.

Once you have completed a port then Known Good Outputs (KGOs) are very commonly used within that single machine, to ensure any output change, even to the most insignificant of bits, is able to be explained.