This package is based on the pure go BLAKE2b implementation of Dmitry Chestnykh and merges it with the (cgo dependent) SSE optimized BLAKE2 implementation (which in turn is based on official implementation. It does so by using Go's Assembler for amd64 architectures with a fallback for other architectures.

It gives roughly a 3x performance improvement over the non-optimized go version.

Benchmarks

Dura	1 GB
blake2b-SIMD	1.59s
blake2b	4.66s

Example performance metrics were generated on Intel(R) Core(TM) i7-3520M CPU @ 2.90GHz - 2 physical cores, 4 logical cores running Ubuntu GNU/Linux with kernel version 4.4.0-22-generic.

benchmark                old ns/op     new ns/op     delta
BenchmarkHash64-4        742           411           -44.61%
BenchmarkHash128-4       681           346           -49.19%
BenchmarkWrite1K-4       4239          1497          -64.69%
BenchmarkWrite8K-4       33633         11514         -65.77%
BenchmarkWrite32K-4      134091        45947         -65.73%
BenchmarkWrite128K-4     537976        183643        -65.86%

benchmark                old MB/s     new MB/s     speedup
BenchmarkHash64-4        86.18        155.51       1.80x
BenchmarkHash128-4       187.96       369.10       1.96x
BenchmarkWrite1K-4       241.55       683.87       2.83x
BenchmarkWrite8K-4       3897.06      11383.41     2.92x
BenchmarkWrite32K-4      977.48       2852.63      2.92x
BenchmarkWrite128K-4     243.64       713.73       2.93x

We can see 2-3x improvement in performance over native Go under varying block sizes.