[citation][nom]enthusiasts[/nom]i wonder how many and which graphics card does it need to power this thing?[/citation]
If I had to guess, I'd guess that it uses four graphics cards, but like I said, that's just a guess. Six displays per graphics card isn't rare (especially for professional AMD cards as this might be using) and any hardware that might be used for running multiple displays per port is extremely expensive, more so than just buying four low end graphics cards, so four is a likely number IMO.