I can only suggest you try different resolutions and settings in the conf.ini as your graphics cards and monitors might need some tweaking to get working faster.
The videos are only guides to give you some idea how others have got it running, personally I did it with Matrox "triplehead2go" set up some time ago back in v4.10
Similar set up to this >>
http://www.ebay.co.uk/itm/matrox-tri...item20f1957876
I have yet to experiment with single or multiple graphics cards HDMI Crossfire or SLI setups.
I'm not sure of your exact configuration or hardware but its not a straight forwards process, but make sure the resolution is supported 100%
My IL2 used to boot normally with THT2G.
Good luck