Minecraft wiki entry for Hopper, associated text: A hopper pipe is simply a chain of hoppers all pointing at each other in a continuous line. This requires extra iron and may cause consistent lag on large scale. Another limitation in Bedrock Edition is that hopper pipes transferring a full load at full speed (for example, continuously moving items that have been stacked in an input chest) will push a small percentage of items past filters without allowing them to be sorted.[1]