Beersmith doesn't know what your boil off rate is until you tell it. There are some profiles that come with it that are a best guess, but you really need to figure that out yourself, and make your own equipment profile.
And, no offence Richard, but boiling as hard as you can?? If you remember, when I brewed at your house, I boiled off an extra half-gallon or so more than I expected...and I had the gas turned down half-way. That was a rolling boil. With my new burner, I boil off about 15%/hr when the gas is turned way down. If I boiled as hard as I could, I'd have 3 gallons of wort at the end of an hour!
I suggest that you get rolling boil going. The surface of the wort should be churning nicely. You don't want it splashing all over the place.