One other thing you can look at is your encoding settings... there are some single-pass and some two-pass encoding options. Within the same codec (for example, H.264 or Windows Media) there is a quality difference between the one and two-pass settings, but honestly, for most porn content, the difference between them is going to be pretty minimal, and it will speed up the time by 25 or 30%.

Also, I am told, but haven't done a head-to-head, that Sorenson (or, for that matter, Compressor, the Mac/Final Cut equivalent) is much, much faster on an equivalently outfitted Mac, because... big surprise... the crappy Windows OS takes a lot of overhead.