I am planning on getting a refurbished computer to run a Minecraft server that usually has around 5 people on at a time, but can get to about 10-12 people on rare occasions. The system will have 8GB of ram, I will use Ubuntu as my OS, and I am going to run a Paper Spigot server in 1.16.1 without pre-loaded chunks, but I am hung up on which CPU I should pick. I have heard all kinds of answers as to how many cores Minecraft uses and seem to have found that Vanilla is primarily single-threaded while Paper Spigot can use more cores to help chunk loading.
The system with the i3-4150 has a 3.5GHz clock speed but only has 2 physical cores while the i5-3470 system has a 3.2GHz clock speed with 4 physical cores. I am having trouble deciding if Paper's ability to use more cores to aid chunk loading is enough to prompt me to go with the higher core count of the i5 or if I should stick with the higher clock speed of the i3.