This may help if your toilet keeps running:
"The most common type of home toilet has a bowl and a water tank. Of these two parts, the water tank is the most complex. Inside the tank are multiple components, which work together to flush and fill the bowl with water. Most problems with a toilet occur here.
The float is one important component inside the water tank. Toilets typically have one of two common types of floats: a filler float or a ball float. ..." For more info and diagrams: HGTVPro - BuildIQ Home Care Guide - Toilets : Overview
And here's a link that takes you to videos, which include a power flush toilet with no performance issues and a composting toilet: HGTV Pro Products Player : HGTVPro.com