There is a fundamental tradeoff between throughput and latency for hash functions. The rapidhash algorithm is clearly optimized for low latency in cases where t

There is a fundamental tradeoff between throughput and latency for hash functions. The rapidhash algorithm is clearly optimized for low latency in cases where the keys are small, like string dictionaries and similar. It is not competitive with throughput-optimized algorithms of similar quality when average keys are several hundred bytes or larger. If you want even lower-overhead, you will need to specialize the hash algorithm for the properties of the key set. I’ve designed narrowly specialized hashes that basically resolve to two instructions. The specifics are somewhat hardware specific but the performance crossover point as a function of key size between latency-optimized algorithms and throughput-optimized algorithms is currently in the 400-500 byte range on modern server hardware, assuming state-of-the-art quality.