Stephan's SqueezeChart statement on LZ4 being the fastest compressor seen on his public benchmark, LZ4 was once again put to the test, this time by Sami Runsas 's Compression Ratings.
This benchmark is very interesting, since its policy is very clear, its benchmark corpus is intentionally heterogeneous and carefully selected (so much that i use it regularly for calibration), and its emphasis on speed and precision makes it a reliable comparison tool, especially for fast compressors.
It is also heavily multi-thread oriented. Therefore, in order to sustain the comparison, LZ4 needed to be upgraded with multi-threading capabilities, since it would stand no chance when running on a single core against the best-of-breed multi-threaded. That's where enters version 0.9....
And it fares pretty well on its first try.
LZ4 gets top position on both compression and decompression speed, while also providing better ratio than previous king of the hill, the excellent 4x4 from Bulat Ziganshin.
And the difference is pretty large : +50% for compression speed, +25% for decompression speed using less than a full thread to max out, and +9% compression ratio.
As a complement, it's interesting to observe that the decoding speed of LZ4 does not vary by increasing the number of threads. That's because decoding speed is so fast that half a CPU usage is enough to exhaust RAMdisk steam.
With such a speed available, compressing/decompressing data costs about the same time as just copying it ... from a main memory RAM Drive. It opens the way to almost free compression for, well, any usage, even on-the-fly compression of temporary data for instance.
LZ4 is available on its homepage.