How to correctly calculate the number of moves per second — 6 games per second × 80 moves or otherwise?

To calculate the number of moves per second, you need to multiply the number of games per second by the number of moves in each game. If you have 6 games per second and 80 moves in each game, then the total number of moves per second will be:

6 games/sec × 80 moves = 480 moves per second.

This is a direct and correct calculation. If the games are running in parallel and the moves are counted cumulatively, then this is exactly how it is calculated.