Yup, and many GCs have the freedom to move objects around due to language semantics so they can do things like munmap pages if they want to rather than calling free.

> Pauses are less than 100ms (usually much lower) which is about the same variation I get from calling a third-party http service.

Note that a pause for calling a web service is different than a GC pause, because in the former you can do other useful things while you wait.