It means that QuEnc is encoding at about 7-8 fps (6 hours enc time - 108 min footage). It is really too slow: my system (Core2 duo T8300 @2.4 Ghz) not far from yours, with same settings (720p, QuEnc CBR 1-pass, DirectShowSource, Lanczos4Resize) goes at about 30-35 fps, resulting in less than 2 hours to encode a 106 min footage.
Check the directshow filters installed. Too many can arise conflicts. I suggest to use ONLY ffdshow and haali as mp4/mkv splitter.
Bye