Numerous issues with 3.0+ I've been having.

[seagull]

Gimp 2.10 worked fine, but then it was auto-upgraded to 3.0+ (I use Linux).

* No more Colorcube Analysis in 3.0+, so I cannot tell how many colors an image has.

* The good process for converting to indexed colors from 2.0+ was replaced with one in 3.0+ that sucks. With the 16-color CGA palette, it makes everything green-tinted. With 3-bit RGB (8 colors), it makes everything darker. And the dithering in Floyd Steinberg has a lot of lines and other distortion that was lacking in 2.0+.

* 3.0.4 does a lot of writing to the drive. About 10 MB just to start up, and hundreds of KB to MB every time I open an image or change a preference. Even 3.0 didn't have that problem.

Meanwhile I "downgraded" to 2.1 and it's definitely an upgrade.

[CmykStudent]

seagull: Hi! Just FYI, Color Cube Analysis will be moved to the Histogram tool in 3.2: https://www.gimp.org/news/2025/06/23/gim...olor-count


I don't think anyone really touched the indexing code in 3.0. My only guess is the color management improvements might have had an impact, though we'd have to review to confirm. Also not sure what could have happened inbetween 3.0 and 3.0.4 to increase writing to disk.

[rich2005]

Which OS ? Auto-upgrade then maybe Fedora ?
The color cube value has been reinstated in the development version, currently Gimp 3.2.RC1 but now in the histogram dock.

   

Apart from that, no problem here, Kubuntu 24.04 / Gimp appimage , converting RGB to Indexed and I have not noticed any excess writes to disk.  Maybe if you give more details someone might spot the problem.