I have purchased a used CNC and I need a larger vacuum for it than what came with it. I have a 10hp regenerative blower for my original one. After looking around I have found that is not hp that determines the amount of vacuum. I found a 20 hp and a 10 hp that both have the same amount of max vacuum.

What I am wondering is what is the benefit of having a 20 hp over a 10 hp if they both pull the same vaccum?