Yes at 1 fps it would not be worth doing, time would be measured in Days, not hours.
I have used Flask quite a bit (thats version 0.6 with 1.1 update) to encode to VCD, to do DivX its always a bit quicker. On my Athlon 1.2gHz under Win2000, I get about 6 to 6.8 fps depending on the movie. Thats for PAL, NTSC is normally a bit quicker as well.
What processor do you have as thats the prime speed determining factor.
Cheers,
ChickenMan