array (fixed): get: 8164µs, set: 14293µs array (dynamic): get: 8334µs, set: 14421µs tuple: get: 1472µs, set: 1603101µs gb_trees: get: 113114µs, set: 212955µs rbdict: get: 8523µs, set: 36555µs orddict: get: 4677552µs, set: 3860µs dict: get: 11223µs, set: 153662µs
The results show that rbdict is worth getting if you need an efficient dictionary implementation in Erlang.
I found a benchmark done by Robert Virding with random input. The input to the benchmark above was not random.