Dishwasher cycle length and number. Remember: Some dishwashers have normal cycles that last three hours, while others take an hour and a half. Sound from a dishwashing machine. For those who spend a lot of time in the kitchen with their families and friends, a quiet dishwasher might be a good option. According to Gordon, you should look for a model that has a noise level of 45 dBA or less. A best dishwashers under $600 noise is measured in dBA units, and the higher the dBA, the louder it is.