Modathon

zlib Updated - FOSE Mod

Link copied to clipboard
zlib Updated - FOSE mod for Fallout 3
Latest27 Feb 2026
Uploaded22 Feb 2026
Version1.1
98.21 KB
Total Files Sizes
0
Unique DLs
0
Total DLs
1
Total Files

zlib Updated - FOSE

File Size98.21 KB
Game Image for Fallout 3
2
Performance Optimization


 

What?

Game uses zlib compression for BSAs, NPC and Landscape records. While you can decompress those, most mod authors don't.

Why is that an issue? Zlib is super slow to decompress, which leads to longer loading times and stuttering.

On top of that, game obviously uses a super old zlib version (1.2.1), which doesn't help.


 

I was bored, and decided to upgrade it to the latest version (1.3.1 at the time of writing), and to my surprise, it's about 2 times faster.


 

Does that mean that you should compress all BSAs now? No, the decompression time is still super slow.

Does that mean that you *can* compress BSAs without being scared of freezing the game every time a cell is loaded? Yea.


 

Port from New Vegas


 

Source Code

GitHub


 

Credits

Jean-loup Gailly and Mark Adler for creating zlib

Instructions

Updates zlib to the latest version for faster loading and less stutter.

Requirements

Permissions and credits

No permissions have been set

zlib Updated - FOSE

Type: Main
Date uploaded22 Feb 2026
File Size98.21 KB
Unique DLs0
Total DLs0
Version1.1

The mod itself