A simple benchmark to test the speed of some popular hash functions, such as MurmurHash, CityHash, and SpookyHash.

The hashers in include/hashers.hpp are basically wrappers of the methods exposed by the SMHasher test suite.

git clone --recursive https://github.com/jermp/bench_hash_functions.git
cd bench_hash_functions
mkdir build
cd build
cmake .. -DCMAKE_BUILD_TYPE=Release
make

Run the perf executable. Some examples below.

• Example 1

    ./perf 10000000
  

  will test all hashers on 10M random 64-bit keys.

• Example 2

    ./perf 10000000 --input ~/Desktop/uk-2005.urls --hasher cityhash_64
  

  will test the hasher cityhash_64 on 10M strings from the file ~/Desktop/uk-2005.urls.

Here are some results I collected on an Intel i9-9900K core (@3.60 GHz), running Linux 5. I used gcc 9.3.0 with all optimizations.

I measured the time it takes to compute the hash function. Results are in average nanoseconds per key.

As input data, I used 100M keys: 64-bit keys, and strings from the GoogleBooks corpus (average string length respectively equal to 13.97 and 19.06 for 2- and 3-grams.)

The suffix _64 and _128 indicates 64-bit and 128-bit hashes respectively.

From these results, cityhash is the clear winner.