How is efficiency calculated?

Efficiency is the ratio between accepted and rejected shares. You can calculate it by formula accepted/(accepted+rejected). It is important to strive towards 100% efficiency, as any lower number means lower stability and less profitability.

For ASICs, the efficiency might become problematic after a while of mining. For such cases, you can set up a trigger that will reboot your machine when the efficiency drops.

Low efficiency can be seen on the worker's profile or by checking the Diagnostic.