Figure 4 — CSV. This figure shows the compression speed vs. ratio tradeoff for the PPMF Unit dataset for OpenZL and three general compression tools, presented as CSV files. OpenZL is able to offer excellent compression ratios, but the cost of parsing CSV caps the compression speed at about 64 MB/s. An improved parser will speed that up, however this strategy will likely never approach Zstd’s speeds of 1 GB/s. Nonetheless and not pictured here, OpenZL always has the option to fallback to the zstd codec, so its performance can be lower-bounded by zstd.