First you will need 3 monitors set at the same resolution. It is recommended, but not required, to have three monitors of the same make/model, though screens that are the same size will work. It is NOT recommended to have three different sized screens as it will be difficult to get the screens to line up properly and could lead to side effects like headaches, motion sickness, etc.
ATI Eyefinity Technology can support up to 3 displays using a single enabled ATI Radeon™ graphics card. To enable more than two displays, additional panels with native DisplayPort™ connectors, and/or certified DisplayPort™ adapters to convert your monitor’s native input to your cards DisplayPort™ or Mini-DisplayPort™ connector(s), are required. They are purchased separately from your video card and are available at most local and online electronic stores.
Make sure to download the most up-to-date drivers for both your graphics card and your version of Windows (7, 8, or 10 — make sure to select the 64-bit option if you’re on a 64-bit version of the OS).
Configuring your monitors
Right click on your desktop and select Catalyst Control Center
Click the "AMD Eyefinity Multi-Display" tab, and then click "Create Eyefinity Display Group".
Next select the type of layout you'd like for your monitors.
3 x 1 landscape setup.
Once you've chosen which layout you want, click 'Continue' in the bottom right hand corner.
Once Eyefinity is enabled. It'll show you what layout you've chosen, and from here you can arrange your desktops
To arrange your monitors, click ‘Arrange’.
Once you’ve arranged the monitors in the correct order click “Done”.
Now log back to the iRacing UI, click on your helmet at the top right and
Then Launch "Run Graphics Config –Launch”
Select "Auto Configure"
Then select the highest resolution in the drop down to match the resolution in your AMD Control Panel (Catalyst Control Center).