xxHash - Extremely fast hash algorithm

xxHash is an Extremely fast Hash algorithm, running at RAM speed limits. It successfully completes the SMHasher test suite which evaluates collision, dispersion and randomness qualities of hash functions.

Branch	Status
master
dev

Branch Policy:

• The "master" branch is considered stable, at all times.
• The "dev" branch is the one where all contributions must be merged before being promoted to master.
  • If you plan to propose a patch, please commit into the "dev" branch, or its own feature branch. Direct commit to "master" are not permitted.

Benchmarks

The benchmark uses SMHasher speed test, compiled with Visual 2010 on a Windows Seven 32-bits box. The reference system uses a Core 2 Duo @3GHz

Name	Speed	Quality	Author
xxHash	5.4 GB/s	10	Y.C.
MurmurHash 3a	2.7 GB/s	10	Austin Appleby
SBox	1.4 GB/s	9	Bret Mulvey
Lookup3	1.2 GB/s	9	Bob Jenkins
CityHash64	1.05 GB/s	10	Pike & Alakuijala
FNV	0.55 GB/s	5	Fowler, Noll, Vo
CRC32	0.43 GB/s	9
MD5-32	0.33 GB/s	10	Ronald L.Rivest
SHA1-32	0.28 GB/s	10

Q.Score is a measure of quality of the hash function. It depends on successfully passing SMHasher test set. 10 is a perfect score. Algorithms with a score < 5 are not listed on this table.

A new version, XXH64, has been created thanks to [Mathias Westerdahl]'s contribution, which offers superior speed and dispersion for 64-bits systems. Note however that 32-bits applications will still run faster using the 32-bits version. [Mathias Westerdahl]: https://github.com/JCash

SMHasher speed test, compiled using GCC 4.8.2, on Linux Mint 64-bits. The reference system uses a Core i5-3340M @2.7GHz

Version	Speed on 64-bits	Speed on 32-bits
XXH64	13.8 GB/s	1.9 GB/s
XXH32	6.8 GB/s	6.0 GB/s

License

The library files xxhash.c and xxhash.h are BSD licensed. The utility xxhsum is GPL licensed.

Other languages

Beyond the C reference version, xxHash is also available on many programming languages, thanks to great contributors. They are listed here.