I was just curious about this topic because I've been searching for an answer for a long time now. I have been curious about what type of CPU should I use for a server with 50+ players (not that I'm ever going to make one with that many players). Is a CPU with many lower powered cores (such as two AMD Opteron 6174 or two Intel Xeon E5-2650 CPU's in a dual socket motherboard) good for for a server of this scale or a CPU with fewer but much more powerful cores (Such as an Intel Core I7-8700) good for a server of this scale?
I'm just curious because I had that question for a while and all the posts I could find where from 2013.
it depends on the type of server and how you configure it base minecraft is not multi-core/threaded but modded servers can take advantage of extra cores and optimized servers can also take advantage of extra cores/threads. but Intel Xeon E3 CPU's tend to be the sweet spot for minecraft servers
But for 50 users, you really need to start looking at Xeon; AMD is fun and cheap, but it's fun and cheap.
So, like, E5-2690 haswell Xeon, dodeca core
What about AMDs Ryzen or thread ripper? I would say personally that with the higher end Ryzen (8 cores, 16 threads) and thread ripper CPUs (up to 16 cores, 32 threads) are making AMD a good choice for servers.