Plenty of scientific simulations end up being IO or communications bound when at scale (e.g. 30k CPU cores). Can hide latency to a certain degree but basically any algorithm that uses timestepping must halt at some point to allow data to flow around the nodes, or to dump data to disk for visualisation or checkpointing.

In saying that there are some novel and very clever algorithms that continue on without seemingly necessary boundary data, that then self correct when the data comes through, thus completely hiding the latency at the cost (in both accuracy and time) of running a correction process.