Try this: Measure how long it takes to fill a bucket with an open ended garden hose turned on full. Then, connect the same hose to a pressure washer and see how long it takes to fill the same bucket. Makes more noise, fills up slower.
Try this. Take the garden hose, time how long it takes to fill the bucket. Restrict the hose outlet 10% and triple the pressure, then see how long it takes to fill the bucket. Your hose, washer theory is getting into the field of Coefficient of Discharge, or CD as it is known.