When you know you're going to be compressing files of particular structure, it's often very beneficial to tweak compression algorithm parameters. In one case when dealing with CSV data, I was able to find a LZMA2 compression level, dictionary size and compression mode that yielded a massive speedup, uses 1/100th the memory and surprisingly even yields better compression ratios, probably from the smaller dictionary size. That's in comparison to the library's default settings.

Could you please provide more details, perhaps give an example?