Important Information

Important Information

This has gained a lot more traction than I thought it would, so there are a few things that need to be cleared up:

What Operating Systems does this work on?

CompactGUI uses the new algorithms introduced in Windows 10, and is therefore limited to this Windows 10 and 11.

I compressed the folder but TreeSize/Spacesniffer still show it as taking up the full space? Why?

Those programs can only read the Folder's size, not the size taken on disk, because that is much harder to read. To see this information right click the folder and go to properties.

Won't this affect the lifespan of my SSD by increasing reads/writes?

Technically yes, but from a realistic standpoint the impact this program has on your drive is going to be neglible. Most consumer SSDs are capable of sustaining at least 20GB of writes per day for over 10 years - You will likely upgrade your computer and SSD several times over before it starts to fail because of excessive writes.

Does this affect performance?

Yes and No. It's compression, so extra CPU power is required to decompress the program files as they're needed, however the XPRESS algorithm is highly efficient and designed for minimal CPU overhead. Any reasonable CPU will have minimal to no performance impact, and those using slower HDDs may even see a performance improvement as the smaller files can be transferred to the CPU much faster for processing. See the Microsoft doc here

I copied/moved the compressed folder but it's no longer compressed. Why?

Compression depends on the files staying exactly where they were. If you move them, they'll get decompressed at the new location. If you copy them, the copies will get decompressed.

Limitations

• This compression may not be permanent - it's a limitation of Windows itself, that the Xpress and LZX functions cannot be run live on new files that are added to the compressed folders. What this means is that over time, with updates to your games, you will experience compression decay; the folder will slowly but surely grow in size until it is back to its original size. You can somewhat get around this by first running Compact on any folder you choose, then run compact.exe /c /s on the folder afterwards which will mark it so that future files will get compressed

  • Note however that this will not use the Xpress algorithm, so the compression of new files won't quite be as significant. This is still better than using the default NTFS compression in Windows ("compress this folder to save space"). HOWEVER, THIS WILL NOT COMPRESS FILES THAT ARE UPDATED IN THE FOLDER. ONLY NEW FILES ADDED WILL BE COMPRESSED.

• Some games don't like this compression - Guild Wars 2 is an example, it compresses down massively, but as soon as you run the game it will hang as it uncompresses the entire game again before it lets you play it.

• Copying files to other systems or syncing to online services will not be compressed - This means that you can safely use this on OneDrive and Google Drive folders, as only the local variant will be compressed. If you copy the files to another drive or computer, they will be decompressed. However If you're compressing files on an external drive, note that those files will only be able to be read on a Windows 10 PC until they're uncompressed again.

• Works on Windows 10 and 11 Only - The features used in this program were only introduced in Windows 10. Earlier OSes will not be able to run this program.