Differences

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--- archive_types [2024/04/27 08:48] – [What is ZSTD?] johnsanc
+++ archive_types [2024/04/27 08:53] – [What is ZSTD?] johnsanc
@@ Line 29: / Line 29: @@
   * It supports multi-threaded compression
   * Its standard levels are 1-19, and ultra levels are 20-22 which require significantly more memory
+  * Its updated periodically, but RomVault uses ZSTD version 1.5.5, which will not change for the foreseeable future in order to ensure deterministic behavior
 ==== How does the compression ratio of ZSTD compare to Deflate and LZMA? ====
-ZSTD level 19 has a compression ratio right in between Deflate level 9 and LZMA level 9. However, since ZSTD is multithreaded its much faster to compress compared to LZMA and often times faster than Deflate. ZSTD also decompresses much faster than both LZMA and Deflate. Example statistics for the redump.org PlayStation collection:
+ZSTD level 19 has a compression ratio right in between Deflate level 9 and LZMA level 9. However, since ZSTD is multi-threaded its much faster to compress compared to LZMA and often faster than Deflate. ZSTD also decompresses much faster than both LZMA and Deflate. Example statistics for the redump.org PlayStation collection:
 ^ Format         ^  Size (GiB)  ^  Compression Ratio  ^  Space Savings  ^
@@ Line 40: / Line 41: @@
 | Solid LZMA 7z  |  2,513.54    |  1.8462             |  45.83%         |
-The diagram below shows the relationship of single-threaded compression speed and ratio. In the case of zstd compression, most use cases would involve multiple workers on modern hardware and compress much faster. The three callouts in the diagram represent the compression levels that RomVault uses for each method.
+The diagram below shows the relationship of single-threaded compression speed and ratio. Most ZSTD use cases would involve multiple workers (threads) on modern hardware and compress much faster. The three callouts in the diagram represent the compression levels that RomVault uses for each method.
 {{:diagrams:zstd.png?nolink&1000|}}
 ==== Why is ZSTD slow when compressing archives with many smaller files? ====