Local agent on 4090 - looking for LM Studio settings

I have moved on from Ollama to just dink around and instead want to start running a local agent from time to time. With the 24GB of a 4090 (Gigabyte OC edition) that should be quite possible. But no matter what settings I use for context and batching, token generation is slow as a snail. Gemma4 is faster, but the quants I tried generated incorrect tokens like </tool_call> (whereas the underscore shouldn't be there afaik).

Any other 4090 user with recommendable settings for a local agent? I do have 32GB DDR4 at 3600MT with a Ryzen 9 3900X.

But - aside from that, I genuenly want to know why those settings work to improve my understanding of the various knobs. Temperature is obviously for the "levels of creativity". But the others are still a little confusing (namely, top_p and top_k for instance).

Thanks :)