Looking forward to use 3 monitors at the same time in Fedora 17 in my HP 110 G6 Server. Added a Radeon HD5450 that can support 2 monitors. I want to use the built in video card so I can hook up the third monitor. Is this possible? I can run either card but not both at the same time...
The on-board graphics use a different driver than your HD5450, and typically you can only have one graphics driver active at a time. In some rare cases motherboards will support this, and the only way to find out is to research your motherboard specifically (example: http://www.techsupportforum.com/forums/f24/can-integrated-graphics-new-graphics-card-3-monitor-set-up-530571.html).
The typical way to get 3-4 monitors going is to get two discreet GPUs from the same manufacturer, which then operate off the same set of drivers.
Another option is to get a USB graphics adapter (like this one: http://www.amazon.com/Smart-Buy-USB-Graphics-Adapter/dp/B001TPIRXC) which can be used to drive the 3rd monitor. This is useful if you don't have a 2nd PCIe slot or a 2nd GPU is cost prohibitive.