Max efficiency portal iron farm

A three layer nether portal iron farm with 36 villagers in pockets and zombies raised and lowered on a redstone clock. Golems spawn on platforms above the pockets and fall straight into portals, which removes them almost instantly and keeps the spawn cycle running at 99 percent efficiency. It comes in two variants, one for 1.19 and one for 1.18.2 and below, and more layers can be added. Java only.

• Build the 1.18.2 variant if you are on 1.20.2 or newer. The 1.19 variant only covers 1.19.x to 1.20.1. Picking the wrong one is the most common reason rates come out low. If you already built the 1.19 clock on a newer version, the creator's fix at nicoislost.com/iron-farm-fix only removes repeaters, nothing else changes.
• The glass above the zombies has to be tinted glass, or another block that stops light passing through. This is in the description, not in the video.
• When you light the portal the boat with the chicken teleports through it. Put the boat in the overworld with two chickens in it and nudge it into the portal with a water bucket instead.
• On 1.21.5 the nether portal hitbox changed and golems stopped teleporting instantly, which wrecks the rate. It was reverted in a later snapshot. On that version a zombified piglin on a rail loop by the portals pulls the golems in.
• Put carved pumpkins on the zombies instead of helmets. Helmets do not keep them alive in the sun for long, pumpkins stop them burning and despawning.
• Do not build it in the spawn chunks, and keep dirt type blocks out of the build, because endermen will pick them up and break it.