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author | Yann Collet <yann.collet.73@gmail.com> | 2015-04-03 22:49:20 (GMT) |
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committer | Yann Collet <yann.collet.73@gmail.com> | 2015-04-03 22:49:20 (GMT) |
commit | 157a739f7ade8b3f41cb2f6aeaa9ca30c376c7ca (patch) | |
tree | 9dc9ff295366749d4af27cf70e3c8acbe4c990ff /README.md | |
parent | 8437a0e43aa5086ec2c23591909e118a85c3d8dd (diff) | |
parent | 43eaf8f33361555f5cbe4306c17a7ca7869c61c8 (diff) | |
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Merge pull request #74 from Cyan4973/fastMode
Fast mode
Diffstat (limited to 'README.md')
-rw-r--r-- | README.md | 92 |
1 files changed, 50 insertions, 42 deletions
@@ -1,60 +1,68 @@ 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. +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 | [![Build Status](https://travis-ci.org/Cyan4973/lz4.svg?branch=master)](https://travis-ci.org/Cyan4973/lz4) | |dev | [![Build Status](https://travis-ci.org/Cyan4973/lz4.svg?branch=dev)](https://travis-ci.org/Cyan4973/lz4) | +|visual | [![Build status](https://ci.appveyor.com/api/projects/status/v6kxv9si529477cq?svg=true)](https://ci.appveyor.com/project/YannCollet/lz4) | + > **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. +> - 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 tests of larger modifications before merge into "dev" branch. Benchmarks ------------------------- -The benchmark uses the [Open-Source Benchmark program by m^2 (v0.14.2)](http://encode.ru/threads/1371-Filesystem-benchmark?p=33548&viewfull=1#post33548) 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](http://sun.aei.polsl.pl/~sdeor/index.php?page=silesia) in single-thread mode. - -<table> - <tr> - <th>Compressor</th><th>Ratio</th><th>Compression</th><th>Decompression</th> - </tr> - <tr> - <th>LZ4 (r101)</th><th>2.084</th><th>422 MB/s</th><th>1820 MB/s</th> - </tr> - <tr> - <th>LZO 2.06</th><th>2.106</th><th>414 MB/s</th><th>600 MB/s</th> - </tr> - <tr> - <th>QuickLZ 1.5.1b6</th><th>2.237</th><th>373 MB/s</th><th>420 MB/s</th> - </tr> - <tr> - <th>Snappy 1.1.0</th><th>2.091</th><th>323 MB/s</th><th>1070 MB/s</th> - </tr> - <tr> - <th>LZF</th><th>2.077</th><th>270 MB/s</th><th>570 MB/s</th> - </tr> - <tr> - <th>zlib 1.2.8 -1</th><th>2.730</th><th>65 MB/s</th><th>280 MB/s</th> - </tr> - <tr> - <th>LZ4 HC (r101)</th><th>2.720</th><th>25 MB/s</th><th>2080 MB/s</th> - </tr> - <tr> - <th>zlib 1.2.8 -6</th><th>3.099</th><th>21 MB/s</th><th>300 MB/s</th> - </tr> -</table> - -The LZ4 block compression format is detailed within [lz4_block_format.txt](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 . +The benchmark uses the [Open-Source Benchmark program by m^2 (v0.14.3)] +compiled with GCC v4.8.2 on Linux Mint 64-bits v17. +The reference system uses a Core i5-4300U @1.9GHz. +Benchmark evaluates the compression of reference [Silesia Corpus] +in single-thread mode. + +| Compressor | Ratio | Compression | Decompression | +| ---------- | ----- | ----------- | ------------- | +| memcpy | 1.000 | 4200 MB/s | 4200 MB/s | +| RLE64 v3.0 | 1.029 | 2800 MB/s | 2800 MB/s | +| density -c1 | 1.592 | 700 MB/s | 920 MB/s | +|**LZ4 fast (r129)**| 1.607 |**680 MB/s** | **2220 MB/s** | +|**LZ4 (r129)** |**2.101**|**385 MB/s** | **1850 MB/s** | +| density -c2 | 2.083 | 370 MB/s | 505 MB/s | +| LZO 2.06 | 2.108 | 350 MB/s | 510 MB/s | +| QuickLZ 1.5.1.b6 | 2.238 | 320 MB/s | 380 MB/s | +| Snappy 1.1.0 | 2.091 | 250 MB/s | 960 MB/s | +| density -c3 | 2.370 | 190 MB/s | 185 MB/s | +| zlib 1.2.8 -1 | 2.730 | 59 MB/s | 250 MB/s | +|**LZ4 HC (r129)** |**2.720**| 22 MB/s | **1830 MB/s** | +| zlib 1.2.8 -6 | 3.099 | 18 MB/s | 270 MB/s | + +The LZ4 block compression format is detailed within [lz4_Block_format]. + +Block format doesn't deal with header information, +nor how to handle arbitrarily long files or data streams. +This is the purpose of the Frame format. +Interoperable versions of LZ4 should use the same frame format, +defined into [lz4_Frame_format]. +[Open-Source Benchmark program by m^2 (v0.14.3)]: http://encode.ru/threads/1371-Filesystem-benchmark?p=34029&viewfull=1#post34029 +[Silesia Corpus]: http://sun.aei.polsl.pl/~sdeor/index.php?page=silesia +[lz4_Block_format]: lz4_Block_format.md +[lz4_Frame_format]: lz4_Frame_format.md |