I've got a Radeon HD 7800 and have 3 17" LCD monitors 2xDVI+VGA 1xVGA only (a real cheapo)
When connecting them I have the option of HDMI/DVI/2xDisplayPort mini
I managed to get the card software to span all three monitors into one for gaming across all three but have not managed to replicate this since. It only managed 1024x768 at that time. I have since managed to get Windows 8 to get me back to all three monitors in extended monitor mode though that itself was a struggle. Any time I try to get into the multiview setup in the AMD software to enable 3x1 mode it disables the two additional monitors then complains that there is a cable issue
It complains about this when I use a DVI-VGA cable or the DPmini-VGA adaptor. I also have in my box of tricks a DPmini-DP adaptor and a DP-DVI cable and a HDMI-DVI cable so I can have two monitors with DVI
Am I stuck with replacing the cheapo monitor with one that has DVI too?