The average number of entities completed per unit time -- the output rate -- from a process is called .

Throughput.

Explanation:

The average number of entities completed per unit time -- the output rate -- from a process is called throughput.

Basically, throughput is a technical term used to describe the amount of data that can be transmitted or transferred from one place to another in a specific period of time. It is used to measure or determine the performance of RAM and hard drives.