If you hate stopping to sharpen your chain then this could be the answer with the Stihl Rapid Duro holding its edge for up to 4x as long as a standard chain.
A special carbide-tipped saw chain that remains sharp for a very long time in frequent use and, above all, in extreme conditions (such as when cutting dirty or frozen wood and in demolition work)
You require a diamond wheel to sharpen these and cannot use a conventional file.
Drive links: 66
Pitch: .325"
Gauge: .050
NOTE: Tungsten, although holds it's an edge for longer than a standard chain it is more brittle. Meaning it is common for you to break tungsten teeth off if you hit something with the chain completely rendering it useless.