I'm unaware of the ability to drive a 4-monitor xorg desktop off of Intel graphics. The user in question here was attempting to do such a thing, which was supposed to be possible with the Nvidia cards. If his/her 'problem' was in purchasing Nvidia cards, then what would your recommendation be for creating such a setup be?
Not the OP, but I think the open source AMD drivers support both DisplayPort and Dual Link DVI, so there's probably several cards from them that would work.
There's always AMD. The open source AMD drivers are great for the 5000 and 6000 series, and support for the 7000 (and by extension 9000) series is getting better.
If you're interested in compute just pick up a 5850 or 5770 from a friend, they're cheap (if you can find them) and they run well with the open source drivers, and have support for at least 3 monitors. My 6850 has 2 DVIs, an HDMI and 2 miniDPs, I can drive 4 monitors at once with it.
I would counter that the AMD drivers are not great. I got a whitebox last year with a 5770, and the experience was terrible. The open source drivers couldn't do 3D acceleration properly, and the proprietary drivers refused to do dual-screen - the maximum available resolution across desktops was a square 1920x1920.
In my experience, nvidia has been providing a superior linux experience in the trenches for the past couple of years. The 'amd is good for linux' seems to be an emotion from yesteryear.
You could just as easily have blamed him for using the proprietary vs free (open-source) drivers, with the same effect (and he still gets better performance).
Seems like your distaste for a company/policy is running this comment.
The Intel graphics are not so fast, but at least a big chunk are open source.