I'm running models locally on my 3090 and it's fast enough, although for example building a vector database can take a while. I can run LoRa training but I haven't done anything meaningful with it so far. I chose 3090 because of the cable issue of 4090 (also, no nvlink, although I'm not sure that matters) but it's debatable if my fears are justified. I need to leave the gpu running while I'm away and I just don't feel comfortable doing that with a 4090. I rather take the lower performance.

One caveat though, my asus b650e-f is barely supported by the currently used ubuntu kernel (e.g. my microphone doesn't work, before upgrading kernel + bios I didn't have lan connection...) so expect some problems if you want to use a relatively new gaming setup for linux.