I have to say that I'm a noob, so please have a patience for me .
I rendered it on 3 machines:
laptop - i7 2670qm, 8 GB RAM, Radeon 7690m (but because of poor driver support, system recognise it as radeon 6700m family), win 7 pro x64; HF2U rendered it for around 46 min.
PC with Xeon e5450 (quad core, 3GHZ), 8GB RAM, GTX 470, win 8.1 x64; HF2U rendered it for 2 hours 40 min. - but for the first time because of the drivers it was more than 6 hours!
HP Z600 workstation - 2x xeon x5650 (12 cores/24threads), 12 GB RAM, GTX 660, win 8.1 x64; HF2U rendered it for 4 hours 25 min.
HF3Pro rendered project on HP Z600 workstation more than 6 hours! And strange articacts started to appear during real time preview (it's laggy).
HF3 is not able to play a simple videoclip smooth on HP Z600 - without any plugin/effect.