I feel bad that I was incorrect about the Multi-World threading. I made sure to verify what I said before I posted it by checking this webpage: http://minecraft.gamepedia.com/1.8 but clearly it's wrong (search it for the word Thread and you'll see what I mean).
But I still wouldn't say the E3's are best for Minecraft because the E5's are faster even in Single Thread. You just need to compare chips in the same architecture and clock speed.
Sandy Bridge -> E5 Faster Ivy Bridge -> E5 Faster Haswell -> E5 Faster.
All in Single and Multi-Threaded scenarios. The reason is simple, the E5's have more cache. That helps with the Single thread performance. CPU Benchmark doesn't tell the full story because the Haswell (E5 v3's) have only been on the market a very small amount of time while the E3 v3's based on the same Haswell microarchitecture have been out quite a considerable amount of time.
I never ever said this though:
And all my reply was stating was that the E3 is one of the best widely available processors to use for the application, and that a 16 core behemoth will not run it any better than a quad-core processor (all else but core/thread count being equal)
What I said was this:
I just want to be clear, I'm not saying the best CPU for Minecraft servers is an 18 core CPU or a 12 core CPU or even an 8 Core CPU. You need a balance of Single and Multithreaded performance.
And I hold that is true. You're using a Quad Core chip, not a Dual Core for example. It's not just about single thread, you need a balance. If you're running a single vanilla server I would argue that even a Quad Core XEON is overkill. A 3.5GHz i3 is more than enough.
But when we're talking about servers with Bungeecord, 70+ plugins, multiple servers (Survival, Creative, Skyblock, Anarchy, Mini-Games etc) that's when those extra cores count. And you also need to remember that when the main thread has to do another task even if its small and short that is an interrupt that reduces the main thread. It's like trying to catch a ping pong ball while riding a bicycle, it'll cause you to slow down and catch it, the more threads you have to handle those kind of things the faster the speed you can maintain.
But again I never said more cores is better than faster cores. I'm maintaining the E3 is not best because with the E5 range you can have both high single thread (which beats E3) and high core counts (33% more than the an E3 with the same clock speeds)