[thatcactusgirl]

I've done some talking with the people over at the Minecraft Storage Tech discord (https://discord.gg/JufJ6uf), and they suggested that we could have a separate limit for open hoppers, active but covered hoppers, and locked hoppers, since they each require different amounts of computing power.

Right now we have 3 concrete rules surrounding hoppers:
- No more than 400 hoppers in a loaded area (11x11 chunks)
- No more than 16 hoppers for an item catching hopper sheet
- No more than 4 hopper minecarts per loaded area (11x11 chunks size)

Open hoppers are the laggiest hopper block, which is why we currently have a 16 limit on hopper catch sheets. I think the 16 per sheet limit is fair since we can use water, but we don't actually have a limit on the amount of them in total. Since this includes hoppers in water streams, hoppers with rails or slabs over them, and any other hopper without an inventory on top, I think our limit should still include a good amount of these.

Active (non-locked) hoppers that have an inventory above them (like a dropper, chest, another hopper, composter, etc) are much less laggy than completely open hoppers, and the exact impact they make on server load depends on the block above it. This is what the video linked in the original post tests, in order to find the amounts of computing load that each block takes.

Locked hoppers (i.e. hoppers that are powered by a redstone source and don't push or pull items) take up the least amount of processing power, and are actually computationally equivalent to any other simple ticking block entity. Basically, they take the same computing power as a furnace.

Here's where my personal opinions come in LMAO
I think these might be reasonable new hopper limits:

- No more than 1000 total open or active hoppers in a loaded area (that's only around 8 per chunk)
- No more than 200 open hoppers or active hoppers with a double chest above it (double chests above hoppers are the laggiest configuration and are about the same computationally as an open hopper)
- No limit on the amount of locked hoppers, since there's likewise no limit on the amount of furnaces and they take up the same computational power

I think the limit on 16 hoppers in a catching sheet is reasonable as they can be substituted for other things, and the hopper minecart rule is also pretty reasonable.

These rules would not only make people use hopper placements that are better for lag (by encouraging people to lock their hoppers when not in use and minimize the use of open hoppers), but it would also allow more complicated redstone builds that are surprisingly low on server usage.
One example of a low-server load machine is this monstrosity: https://www.youtube.com/watch?v=LV3F2-VsZFY Even though it technically uses 1580 hoppers, 90% of them are locked at all times, so it has the same server load as 158 hoppers (about the same as one and a half /warp smelt's) Not saying that everyone should go out and build something like this, but it would be fun for the redstoner players to have a big goal such as this.