In my Modular Simpit, the visuals system consists of 5 LCD screens: Three 17" LCD's for the scenery display, and two 15" LCD's for the panel display.
It is possible to run all 5 screens from one PC: My system consists of an Atlon 3GHz board, with one powerful PCI express GFORCE7800GTX video card and another PCI GFORCE8400GS card. Both Cards are dual head types.
The GFORCE7800GTX video card sends out two signals: One very wide 3840x1024 signal and one 1024x768 signal. The GFORCE8400GTX video card sends out one 1024x768 signal, the other output is not used.
The very wide 3840x1024 signal goes to the Matrox TH2Go box, and this box splits the signal into three 1280x1024 signals, that go to the three 17" scenery monitors.
The two 1024x768 signals drive the two 15" LCD monitors that make up the panel.
Below diagram shows this setup.
PC rear with the outputs of the two video cards.
After installation of all hardware and software drivers (and some tweaking), your computer properties menu will look like something below (apologies for the Dutch Windows XP version)
The #2 and #3 monitors are extended to the main desktop. When you run FS9,
you can undock the cockpit panel view, and drag it to the two 15" monitors.
The main cockpit outside view stays on the three 17" LCD's.
My setup has the two 15" LCD's next to each other, and the flight-yoke just in between them. By placing the instrument panel partially over the left and right monitor, you get a panel / yoke position that matches an actual GA setup.
This video describes the visuals setup and explains the use of Triple Fresnel lenses in some detail.