Decompressinator is a batch script that uses PSARC (Sony PlayStation SDK Tool) and NMSResign to automatically process the game .pak files by unpacking them and repacking with compression disabled.
This, in most cases, will significantly improve game performance by eliminating CPU spikes caused by on-the-fly .pak decompression without running the game files fully unpacked, which is another method that itself introduces significantly longer loading times due to the file system strain caused by the game needing to open handles to thousands of files.
In most cases, it completely eliminates commonly experienced lag spikes when leaving the atmosphere of a planet, calling in freighters, and many other similar lag spikes that occur when the game needs to decompress data from a .pak file during gameplay. It may also improve loading times more generally, such as when loading into a save file, warping from system to system, or using teleporters. Because it addresses these lag spikes, other similar mods that also address these things are rendered moot by using this, so adjust your mods folders accordingly.
So, how and why does this work?
Basically, this improvement happens because decompressing and repacking the files as is, you are dropping the requirement for the game to spend CPU cycles on decompression during any loading situation, and are instead relying on your disk's raw read speed to get the necessary files instead. Decompressed .pak files are much larger than compressed .pak files, so it's highly recommended you store No Man's Sky on a very fast reading disk, such as any decent quality SSD from a reputable brand. Extremely poor quality/no-name brand SSDs and slow or fragmented mechanical hard disks may actually see performance losses in some cases if this script is used, since the reason the performance gains occur depends on having fast file access to begin with. Because of this, the amount of improvement this has on performance is variable from computer to computer, but assuming you are running the game from any even half-decent SSD, even older SATA ones, it should improve performance and reduce lag spikes as intended.
Obviously this performance boost comes at the cost of storage space. Uncompressing the files will roughly triple the amount of required storage space. As of No Man's Sky Worlds Part 1, assuming you delete the backup of the compressed files afterwards or ran with the -no-backup argument, the game takes up ~44.8GB of storage total.
-force.)-no-backup, which also slightly reduces the required free space footprint during runtime by a bit.)BankSignatures.bin.NMS-Decompressinator.bat, psarc.exe, and NMSResign.exe over to your No Man's Sky\GAMEDATA\PCBANKS folder..pak files will consume 44.7GB of additional storage.NMS-Decompressinator.bat.PackedFileBackup folder to reclaim the storage space that the original packed files take up.After updates or changing beta branches, you may see a "File Tampering" warning upon starting up No Man's Sky. You can simply run the script again anytime to unpack the updated files and get rid of the Tamper warning. Running the game without rerunning the script shouldn't cause any problems, but it's definitely recommended you run the script again after updates, since updates will cause the .pak files to become stock compressed ones again whenever they are updated.
Subsequent runs of the script should also be faster, as it tries to skip files that haven't been updated by checking file timestamps. This behavior can be bypassed using the -force argument.
Happy Exploring Travelers!
If you think you've found a bug, run into some sort of problem, or otherwise need some sort of help, feel free to submit an issue or post a comment in one of the following places (in order of my preference):
If the issue you're having occurs after the script seems to have completed successfully, please provide a copy of your BankSignatures.bin file with your issue, as it can usually help me debug the problem. On Discord, you can just send me the file directly in DMs, on GitHub you will need to zip this file to upload it to your issue, and on NexusMods you can zip the file and provide a link to it on your favorite publicly accessible file hosting service, such as Google Drive, Mega, Dropbox, or my preference: Catbox's Litterbox service, set to 3 days so I have time to download it.