Mod Compressor Tool for MO2

Mod Compressor Tool for MO2

— a powerful plugin for Mod Organizer 2 that utilizes native transparent compression in Windows 10/11 (WOF — Windows Overlay Filter). This allows you to significantly reduce the disk space occupied by mods and potentially speed up game loading times.

>> Test Version (Beta)

Key Features

• []Transparent Compression — files behave as usual, requiring no manual extraction.[/]

  []Batch Processing — compress/decompress hundreds of mods simultaneously.[/]

  []Intelligent Targeting — selective compression for textures, models, LODs, sounds, or the entire mod.[/]

  []Multiple Algorithms — ranging from fast (XPRESS4K) to maximum (LZX).[/]

  []Real-time Statistics — compression ratios and space savings per module.[/]

  []Fully Reversible — complete restoration via decompression.[/]

  []MO2 Integration — seamless support for profiles.[/]

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  How It Works: The Science

  Traditional Storage vs. Compressed Storage

  When installing mods, Windows stores each file in blocks called clusters. In the NTFS file system, the default cluster size is 4 KB. This means:

  • []100-byte file → occupies 4 KB → 3. 9 KB wasted (97%)[/]

    []2 KB file → occupies 4 KB → 2 KB wasted (50%)[/]

    []5 KB file → occupies 8 KB → 3 KB wasted (37%)[/]

    The Small File Problem: A typical texture mod contains thousands of small files (LOD textures, normal maps, etc.). A mod containing 10,000 files of 2 KB each wastes about 20 MB just on "cluster tails" (slack space)!

    Advantages of WOF Compression:

    • []Data Compression — content is compressed (typically 2-4x for textures).[/]

      []Cluster Optimization — multiple compressed files can share clusters.[/]

      []Transparent Access — Windows performs on-the-fly decompression; applications see regular files.[/]

      []CPU vs. I/O Trade-off — modern CPUs decompress data much faster than storage drives can read raw data.[/]

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      Performance: Can Compression Speed Up Loading?

      Yes, in many cases!

      Paradoxically, compressed files can load faster than uncompressed ones: the bottleneck is usually the storage drive, not the CPU.

      Uncompressed: → → Done

      Compressed: → → → Done

      • []HDD (100 MB/s) — Slow read speed → ✅ Compression wins[/]

        []SATA SSD (500 MB/s) — Medium read speed → ✅ Compression usually wins[/]

        []NVMe SSD (3000+ MB/s) — Fast read speed → ⚖️ Roughly equal[/]

        Real-world Example: LOD Files

        LOD files are perfect for compression:

        • []Thousands of small files (512 B - 8 KB).[/]

          []High compressibility (repetitive data patterns).[/]

          []Sequential loading (the game loads many files at once).[/]

          Skyrim SE Setup Example:

          • []DynDOLOD output: 2. 1 GB → 680 MB (68% savings)[/]

            []Loading time (HDD): 47 sec → 31 sec (34% faster)[/]

            []Loading time (SSD): 12 sec → 10 sec (17% faster)[/]

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            Comparison: WOF vs. BSA/BA2 Archives

            WOF Compression:

            • []Compression Ratio: Good (2-4x)[/]

              []File Access: Individual files[/]

              []Mod Conflicts: Standard MO2 resolution[/]

              []Editing: Direct[/]

              []Compatibility: Universal[/]

              []Partial Updates: Update individual files[/]

              BSA/BA2 Archives:

              • []Compression Ratio: Good (2-4x)[/]

                []File Access: Only through the archive[/]

                []Mod Conflicts: Complex priority rules[/]

                []Editing: Requires repacking[/]

                []Compatibility: Game-specific[/]

                []Partial Updates: Entire archive must be repacked[/]

                Usage Recommendation: Use WOF to check mod functionality during development/testing; use BSA for final releases or stable builds.

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                Compression Algorithms

                • []XPRESS4K — ⚡⚡⚡⚡ Fastest processing, roughly 1. 5-2x faster compression. For NVMe users.[/]

                  []XPRESS8K — ⚡⚡⚡ Fast compression, about 2-2. 5x ratio. Recommended.[/]

                  []XPRESS16K — ⚡⚡ Medium compression, about 2. 5-3x. Good balance.[/]

                  []LZX — ⚡ Slower processing, about 3-4x compression ratio. Maximum savings for HDDs.[/]

                  Storage Recommendations: