Hoppers causing CPU lag

Large amounts of hoppers cause CPU lag in servers.

What I expected to happen was...:
Hoppers would not cause as much lag in servers

What actually happened was...:
The more hoppers placed in a concentrated area seem to increase server CPU usage dramatically.

Steps to Reproduce:
1. Start a Minecraft server
2. View the CPU usage before
3. In the Minecraft server, place a large amount of hoppers in an area.
4. View the CPU usage after

Although it may not be as much an issue on small servers, Some larger servers have had use a mod to reduce hopper updates to 1 per 10 seconds due to this issue.