> 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.

> The benchmarks [1] 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 IO.

> As of the time of this writing, IO is significantly faster than or at least comparable to all other purely functional solutions.

https://zio.dev/docs/overview/overview_performance

[1] https://github.com/zio/zio/tree/master/benchmarks