5x faster depends on the context with such benchmarks. They are only useful for file or big buffer digests, but not for the general usage in a hash table, with small buffers and needed small code size. FNV1 still beats all those bigger hash functions, based on the new crc32c or aes intrinsics.

So, CityHash is deprecated. If you want to ask, ask about FarmHash, its successor. MetroHash beats it. MetroHash also beats xxHash64 in all aspects.