zio has excellent performance, featuring a hand-optimized, low-level interpreter that achieves zero allocations for right-associated binds, and minimal allocations for left-associated binds.
benchmarks project may be used to compare
IO with other effect monads, including
Future (which is not an effect monad but is included for reference), Monix
Task, and Cats
As of the time of this writing,
IO is significantly faster than or at least comparable to all other purely functional solutions.