I have 27 Pawns, over 30 animals. On a fairly large size map. And the game runs butter smooth! Just upgraded from a I7 7700K - No overclocking and the performance difference is absolutely amazing. I'm running like 65+ Mods as well! lol
Not sure if Ram Speed plays into it. But I will report that I'm currently running 64GB 3600Mhz C18. I know 32GB is more then enough for gaming. And Rimworld does not use a lot of Ram. You won't need more then 32GB for any games really. Unless you get into some Editing/Render type work too. But the 3600Mhz and C18 are the important aspects to take away here. If you don't know the graphics card is not that important for Rimworld. So I imagine it's mostly CPU, some Ram.
But this was an impressive performance boost. I loaded my save file from my previous build. And it used to lag non-stop. It's so smooth now. But just reporting this so others know that if Rimworld is basically your favourite game. Don't hesitate to get the most powerful processor you can afford. And I believe single core performance is key.
Single Core Performance is what you want to aim for when it comes to Rimworld. I think. Correct me if I am wrong. So in general Intel is better then AMD but it still comes down to the specific CPU.