Cost vs return - aka worthiness debate

[artag]

lzma2 does skip uncompressable blocks, stated by the author

https://sourceforge.net/p/sevenzip/d...read/2f6085ba/


simple tests:

take an uncompressable mp4 file, rar , mkv or something like that


compres with lzma:256m and 7zip:d=256 (set mnt to two if you want to test
both algorithms on same conditions)

do some tests with different uncompressable files

the lzma will compress very little and sometimes will be bigger (because
overhead added to not compressed blocks)

lzma2 will be smaller and on the worst case only a few klobytes larger

do an extraction test of the compressed files, lzma2 is faster (uncompressed
blocks are just copied to output)

and finally, this is a test on single compression algorithms, if you use one of the
built-in methods on FA, you are combining a chain of algorithms/tools, that is another
different thing. That's not what i'm talking about

yes i have a four core cpu, if you invoke 4x4:lzma:256m on quad core or i7, well
32 bit fa will fall beyond memory limits (i'm aware of 64bit fazip but i haven't tested it yet)

lzma on FA and lzma2 on 7zip is single thread decompression, cpu usage confirms that, also author

https://sourceforge.net/p/sevenzip/f...requests/1095/

what is rz?

any coments of somebody with experience with zstd or lzham (combined with FA)

http://www.fileforums.com/showthread...464#post465464


quick compare (single mkv file, expect better results with something with mixed compressable-uncompressable blocks like game assets or 3d models-scenes):