Hey there.
I put a 100% Vanilla Minecraft server up in my spare bedroom some months back and have been educating myself on the details of being an admin in this environment. We started on my extra R5-2600 and 16GB of ddr4-3000 and a terrible sata ssd. I've upgraded us to a good Samsung NVME drive and doubled the system memory, allocating as much as 24GB to Minecraft if needed. We also upgraded to a 3600X I am trying to improve performance continually while also improving the experience. Currently the draw distance on the server is 18 chunks. When my small group of players is online I am pretty easily able to outfly the redraw of the server.
My question is, would a 3900X handle this better simply because it has twice the cache? The small increase is clocks would help slightly, but it's the cache that I think would actually make a noticable difference in gameplay. Is this a reasonable assessment? Can I borrow an R9 processor from someone just to test this? Yes I am serious and would treat the loaned hardware with the utmost respect and replace it in the unlikely event of a failure.