Steam is planning to use a new type of compression called zstandard (ZSTD) for downloaded game files. Right now, Steam uses a different compression method called LZMA (Lempel-Ziv-Markov chain Algorithm) for chunks of game data that are 1MB in size.
The change was shared in a post by the creator of SteamDB, Pavel Djundik, on Bluesky. This is meant to make downloading and unpacking games faster for users. LZMA and ZSTD are both ways to compress data. LZMA can make files much smaller, but it takes longer to compress and decompress them.
On the other hand, ZSTD strikes a good balance. It’s much faster than LZMA, so while it might not compress files as much, it still beats many other quick compression methods. This speed advantage is especially useful for downloading game chunks on Steam, as it helps reduce the time it takes to download and unpack games.
This makes ZSTD an arguably better option, even if the files are a bit larger compared to LZMA’s highly compressed files. This improvement can also make a noticeable difference for devices like the Steam Deck, which is likely why Steam focused on it. Faster downloads to Steam Deck mean happier users.
This change in compression algorithms could also be influenced by the need to save costs, especially for games that don’t have many active players. A simpler algorithm like ZSTD could help lower server expenses compared to more resource-heavy options like LZMA.
This approach is similar to what Arch Linux did a few years back, but it was from XZ to ZSTD. The team explained at the time, “Recompressing all packages to zstd with our options yields a total ~0.8% increase in package size on all of our packages combined, but the decompression time for all packages saw a ~1300% speedup.”
We still need to see how much the overall performance gets better. Steam may just be testing this on a few games for now.
Source: Pavel Djundik/Bluesky
