Versions tested: 0.2a
Optimal parameters: lzma:32m:ht4:mc16
Links: http://freearc.org
Authors: Bulat Ziganshin
Algorithms: LZ+HUF, LZ+ARI, BWT/ST+MTF/WFC
Notable peformances: Application1, Application4, Game1, Game2, OS1, Pitches1, Text2

4x4

A parallel driver for the compression library used in freearc. The quote below is from the program version history that mentiones some of the features:

0.1 Multithreaded compression
Overlapped I/O
Tornado and LZMA:ht4 are used
Blockwise compression

0.2 Fast compression modes made even faster
* direct i/o to compression buffers
* larger blocks to avoid disk trashing
* MM tables disabled in -2/-3 modes
Multi-threaded decompression, also with direct i/o
Fast text compression modes 1t..4t using grzip
* now 4x4 is 10x faster than lzturbo on ENWIK9!
Win32 & Linux versions

0.2a Fixed bug in Tornado

0.2a 4x4-history.txt

 

(Have info that should be added here? E-mail.)


0.2a freezes decompressing Audio1. Compressing with some of the presets (6 and upwards) fail possibly due to out of memory.

Qualified configurations
Ver Rating CPR DPR S.E. R.E. Ratio C. kB/s D. kB/s
1
0.2a 0 0 0 253 0 1.805 310201 334859
2
0.2a 24 41 4 902 0 2.383 246439 279141
3
0.2a 65 106 11 1182 0 2.556 220626 289757
4t
0.2a 104 171 18 209 2 3.273 15323 19786
lzma:32m:ht4:mc16
0.2a 455 449 543 281 56 3.848 7538 107764
Disqualified (why) configurations (with qualification ratings)
Ver Rating CPR DPR S.E. R.E. Ratio C. kB/s D. kB/s
4
0.2a crash while decompressing (aud1)
5
0.2a crash while decompressing (aud1)

Version info

0.2a, tar: yes, mode: 32-bit, crc32: 6b845133, decoder: 236 kB, tested: 2010 Apr 17
compression: 4x4.exe -p4 <args> <src> <cfile>
decompression: 4x4.exe d -p4 <cfile> <src>