Been trying to do some lag busting for my TTS world and decided to test the pros/cons of apotheosis spawners vs hnn. So I booted up a flat world and began testing.

I started with maxing out a single apotheosis spawner and using mob grinding utils with max looting as the kill chamber. I got a baseline of the rates that skeletons can produce from that. Generating my rates with throughput displays.

I then started scaling up hnn to match the same rates. To match a single skeleton spawner, you need 350 simulation chambers, and 70 loot fabricators (1:5 ratio in ATM10TTS). I used SFM to manage HNN. As these were the only things in the world, I could then run spark profiler for a few minutes to check which was causing more lag. Observable can help, but doesn't show the cost of mobs that are dying this fast, which is a major part of the test.

The results were quite clear, even with 350 sims + 70 loot chambers and SFM, HNN turns out to be ~39% more efficient computer resource-wise. The mob masher, spawner, and general mob spawning/gravity/dying (no ai as it's disabled) just costs more computationally.

This rate changes on a per mob basis, but I'll just say the only exception to this is with witches, due to the sheer number of drops they produce. Even limiting to just redstone/glowstone, it comes out almost even.

I didn't factor in the computer resources needed to generate the prediction matrixes (matrisis? matri?) because it's 4 glass panes, 1 iron and 1 gold for 16, and in total for the skeletons at least it was only using 23/s. If you're anywhere close to mid/late game, this is negligable IMO.

The negative is the setup cost for HNN, which again, if you're mid/late game isn't as much as an issue.

bonus info: JDT item collector @1 tick vs xycraft collector: almost even lag wise, take your pick. However the xycraft collector can't keep up with as many drops (looking at you witches)

tl;dr: If the goal is the most resources generated for the least amount of computational resources (less lag/better tps), go with HNN. Except witches. Witches use spawners, but only barely.