Make Minecraft zombie farm more resource-efficient?

I sometimes have the problem on my Minecraft server that the tps drop extremely when there are a lot of zombies in my case. Have Bukkit on it, is there maybe a version that saves resources?

There's enough free RAM and the CPU is not yet fully utilized

What exactly do you need the zombie farm for? Maybe there's a better farm for your benefit.

_________________________________________________________________

My Minecraft channel:

https://www.youtube.com/...o0CAN7RnEA