> So I don't see why Haskell's additional allocations should cause GC to be any more of an overhead.
In this kind of garbage collector, time of an individual garbage collection should not depend on the amount of garbage that has been generated. However, producing more garbage should mean more frequent collections, and so more time spent in GC overall.
In this kind of garbage collector, time of an individual garbage collection should not depend on the amount of garbage that has been generated. However, producing more garbage should mean more frequent collections, and so more time spent in GC overall.