Evilnat Custom Firmware (CFW) on a PS3 is generally compatible with most models, especially the older "fat" PS3s, but compatibility depends on the console's model and minimum firmware version. Fat PS3s, in particular, are often compatible with Evilnat CFW. Slim and Super Slim models have specific compatibility requirements, including minimum firmware versions, and may not all be compatible with Evilnat. 

Here's a more detailed breakdown:

General Compatibility:

Fat PS3s:

Generally compatible with Evilnat CFW. They often have a minimum firmware version of 3.56 or lower.