Sure, if you look at the Pareto frontier for xz and zstd, zstd does not seem like a “replacement” for xz. It’s not a replacement for PPMd. The problem is that

Sure, if you look at the Pareto frontier for xz and zstd, zstd does not seem like a “replacement” for xz. It’s not a replacement for PPMd. The problem is that xz has kind of horrible performance when you crank it up to the high settings. On the medium settings, you can get the same ratio for much, much less CPU (round-trip) by switching to zstd. YMMV, use your own corpus and CPU to test it.