I have an NVidia GTX 480 graphics card. I have two Matrox TripleHead2Go screen extender units connected to the DVI output headers on the card. I have 6 ASUS HDMI monitors.
The Matrox units are configured to extend the Windows 7 desktops across all 6 monitors. I can move the cursor and any open window to any of the screens. However, when I try to run Microsoft's FSX the app only displays in one of the 3-monitor sets.
I checked with Matrox and they told me that my GXM setup was correct but they indicated that I needed to "stretch" the output from the two DVI headers into one stream so that FSX would run on all 6 monitors at the same time.
I can find no references to "stretching" the outputs from my graphics card so that FSX will run on all 6 monitors.