It really depends on what and how you're encoding. Are you using Avisynth? If so, what filtersets do you have, and what order do you have them in. If I put certain filters before a resize, it can double the encoding time. Also, if you're adding options in tmpgenc, to remove ghosting, or
deinterlace, this also adds considerable time.
On average, with my p3 650 laptop, I'm getting about 3.25 hours per hour
of movie that I'm encoding. (I really need to get a faster system
)
There is also a cache setting under Environmental Settings, that should speed things up for 2pass vbr. I turned it on, on my box, and things seem
faster, but I didn't really start paying attention to time, until recently. Usually I'm starting the encode before going to bed.
good luck
-Jeff