It's a four core CPU, not sure which, with 12gb of ram and an SSD for storage. A few people are a few hundred blocks away from spawn and the rest of us are close to each other. I generated 6000x6000, about 200 chunks, before we started playing, nobody has been that far yet. On the 1.11.2 server we had, same specs and same situation with players being a bit spread out, we had no lag at all.