Mob cap in the hundreds to over 1000 per player.
This is at my [Guardian Farm| on a vanilla server. TheĀ [entity cap| has no reached way higher than it possibly should. !image-2019-05-13-18-33-55-790.png! ] 
I don't think the operating system I use matters, since it's on a server and not singleplayer. The entities keep rising the more I stay in the area.
I should also mention the server's chunk rendering distance is set to 4, and the mob cap was never changed by the owner.