2.6 KiB
LZ4 - Extremely fast compression
LZ4 is lossless compression algorithm, providing compression speed at 400 MB/s per core, scalable with multi-cores CPU. It also features an extremely fast decoder, with speed in multiple GB/s per core, typically reaching RAM speed limits on multi-core systems. A high compression derivative, called LZ4_HC, is also provided. It trades CPU time for compression ratio.
| 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. Direct commit to "master" are not permitted.
- Feature branches can also exist, for dedicated testing of larger modifications before merge into "dev" branch.
Benchmarks
The benchmark uses the Open-Source Benchmark program by m^2 (v0.14.2) compiled with GCC v4.6.1 on Linux Ubuntu 64-bits v11.10, The reference system uses a Core i5-3340M @2.7GHz. Benchmark evaluates the compression of reference Silesia Corpus in single-thread mode.
| Compressor | Ratio | Compression | Decompression |
|---|---|---|---|
| LZ4 (r101) | 2.084 | 422 MB/s | 1820 MB/s |
| LZO 2.06 | 2.106 | 414 MB/s | 600 MB/s |
| QuickLZ 1.5.1b6 | 2.237 | 373 MB/s | 420 MB/s |
| Snappy 1.1.0 | 2.091 | 323 MB/s | 1070 MB/s |
| LZF | 2.077 | 270 MB/s | 570 MB/s |
| zlib 1.2.8 -1 | 2.730 | 65 MB/s | 280 MB/s |
| LZ4 HC (r101) | 2.720 | 25 MB/s | 2080 MB/s |
| zlib 1.2.8 -6 | 3.099 | 21 MB/s | 300 MB/s |
The LZ4 block compression format is detailed within lz4_block_format.txt.
For streaming unknown amount of data and compress files of any size, a frame format has been published, and can be consulted within the file LZ4_Frame_Format.html .