Hi danybr !
I remember it took 5h more or less for me for each feet at 0.2mm, 90mm/s and 50% infill.
There is tons of other settings that can affect print time like number of perimeters etc... Don't know what to answer, sorry !
It's weird that S3D say 3h20 and it take 8h30...
S3D is pretty accurate for me :/