Prior to Minecraft 1.5, item transfer was difficult and incomplete without using mods like BuildCraft, RedPower, or Thermal Expansion. You could use minecarts to get items from point A to point B, but you had no way to transfer items from one inventory to another, meaning items had to remain in the minecart until you moved them manually into a nearby chest (unless, again, you used a mod – specifically RailCraft). The same was true of water canals: you could move items from, say, a mob grinder to a place inside your base, but you couldn’t deposit said items within a chest.
That all changed with the introduction of the hopper in the 1.5 update. Some of you may remember that the BuildCraft mod had already introduced a hopper prior to the 1.5 update whose function was pretty much to be a buffer block (desperately needed because of certain quirks in the way BuildCraft pipes worked), but the hopper that Mojang introduced into the vanilla game in 1.5 so perfected the idea of the hopper that BuildCraft actually removed their own hopper in subsequent versions of the mod. Hoppers along with two other items introduced in 1.5 – the dropper and the comparator – made possible some pretty sophisticated item transfer and sorting systems, about which I’ve posted several times. At the core of these systems are two basic ideas: the hopper chain and the dropper chain.
Now, I love hopper and dropper chains, but they have one important limitation: the speed of transfer is basically fixed. There aren’t these convenient upgrades such as you can craft in many mods to increase the volume and speed of item conduits. A hopper transfers items at a fixed rate of 1 item per 8 game ticks (= 1 item per 4 Redstone ticks, or 1 item every 0.4 seconds of real time). Dropper chains can transfer items slightly faster because they are operated by a Redstone clock (generally a comparator clock) which can pulse faster than once per 4 Redstone ticks. Even so, the rate of transfer is basically the same in the grand scheme of things.
Increasing the Rate of Transfer By Increasing the Size of the Pipe
But what if I want items to move faster than this? Is there anything can be done? Actually, yes. While we cannot make hoppers or droppers faster, we can double and even quadruple the speed at which items are transfered by doubling or quadrupling the size of our conduit, so to speak. In other words, instead of one line of hoppers or droppers taking items from point A to point B, we can use two or four parallel lines of hoppers or droppers.
Example A: Two Double Chests and a Bunch of Hoppers
All of these examples begin with a double chest on two hoppers. Every 8 game ticks, each hopper will pull one item from the double chest, meaning twice as many items are being pulled and transferred every 8 game ticks. In Example A, these two hoppers simply lead into two parallel hopper chains, both of which finally deposit into a common destination inventory.
Example B: Two Vertical Dropper Chains
Dropper chains are a little more complicated than hopper chains because they require a Redstone pulse wave to go through the whole chain, “pushing” items through the chain to a destination inventory. It’s easy enough to divide items into two non-adjacent dropper chains, doubling the rate of transfer, but with a little smart Redstone engineering, this can be done even with adjacent dropper chains.
Example C: Two Horizontal Dropper Chains
Horizontal dropper chains are more complicated even when dealing with just one chain, but they are potentially slightly faster than vertical dropper chains. Non-adjacent parallel chains are not too difficult to execute. Adjacent chains took quite a bit of experimentation, but ultimately I stumbled upon a design that works.
Example D: Two Droppers Transferring Via Water Canals Over Ice
You can use droppers to shoot items out into a water canal running over ice blocks and terminates in hoppers. This can actually be an extremely fast way of transferring items.
Example E: Four Droppers Transferring Via Water Canals Over Ice
Finally, it is possible to distribute items from a double chest evenly into four droppers and to use a single comparator clock to send four streams of items out into a four block wide water canal over ice blocks that terminates in four hoppers leading into a common double chest. This method of item transferral is insanely fast for vanilla Minecraft.
What About Slowing Things Down?
Sometimes, for various reasons, you might want to slow down the rate of transferral. That’s easy to do with dropper chains: you just decrease the rate of your Redstone clock by right clicking a repeater or inserting a repeater where there hadn’t been one. But what about hoppers? Can they be slowed down?
Actually, yes: by using a Redstone clock to intermittently restrict item transfer. Here’s an example.
Before doing these experiments, I don’t think I had a full appreciation for just how remarkably versatile item transfer systems could be in vanilla Minecraft. I wonder whether it might possible to increase speed even beyond 4x.