Why is a variable speed compressor better than a fixed compressor?

Most units come with a variable speed compressor, which is a compressor that adapts to the needs of the unit. With a traditional fixed compressor, the motor runs at full speed when the compressor kicks on. A variable speed compressor adapts its speed to the demand of the cabinet. During a service rush, door openings increase, and the compressor will adapt by running at full speed. At night when the cabinet is closed, the compressor will run at a lower speed to maximize efficiency.