AFAIK an important factor to get good performance out of a hash table is to dimension the table so that collisions are rare. In this scenario it's not too surpr

AFAIK an important factor to get good performance out of a hash table is to dimension the table so that collisions are rare. In this scenario it's not too surprising that the additional cost of sometimes having to iterate through the table beats chasing pointers. Furthermore as the article explains they can use SIMD to search several buckets at once, something that wouldn't really be possible if they didn't exist in contiguous memory.