Responsiveness
The first thing to look at is how responsive your product is. Research is pretty consistent on this topic. If an action takes less than 0.1 second to finish, the user perceives it as instantaneous. If it takes less than 1 second to finish, the user no longer perceives it as instantaneous but will not lose track of what is going on. If an action takes longer than a second, the chance increases that the user gets distracted while waiting for it to finish.[115]
Whenever possible, it’s best to make sure actions take less than 0.1 second.
A somewhat related topic is continuous interactions on natural user interfaces, such as scrolling through a list by dragging the list with a finger. In those cases, performance is especially important. ...