There's a performance penalty which happens if you don't need async (eg, if the innermost thing is actually using Task.FromResult), and I've never tested but th

There's a performance penalty which happens if you don't need async (eg, if the innermost thing is actually using Task.FromResult), and I've never tested but there's probably some cutoff point where if an awaited operation is faster than x, it's faster to write non-async code (though x may vary by cpu or some other factors). Practicality speaking, this isn't much of a concern for most code, though. I've only really run into this in a couple specific scenarios: unit tests, and when using something like a message bus or cache layer that has a local/in-memory implementation. I noticed only incidentally (as opposed to because of a perf problem): on unit tests where the time got slightly longer when we changed to async, and in the message bus case when doing some performance profiling and using the "local" dev version.