You will need
- drivers motherboard;
- drivers graphics cards;
First, make sure that the motherboard of your computer supports synchronous operation of two graphics cards. Refer to the documentation to the motherboard. Find notes CrossFire or SLI. These modes are used for video card companies, ATI and Nvidia, respectively.
Select display adapters, of which you will synchronize. It is important to understand that this situation is not suitable for all graphics cards. Buy two graphics accelerators from the same manufacturer.
Make sure that the video cards support dual-channel mode. When choosing a video card ATI (Radeon), you can use cards of the same series. This means that the devices should have approximately like this: Radeon HD 5xxx.
Remember that the real performance of a more powerful graphics card will be reduced to a weak adapter.
Turn off the computer. Install both video card in the PCI-Express slot. In this situation, the monitor cable should connect to the devices via a special adapter. Standard display connection to the video card will not improve the performance of the graphics devices.
In that case, if you plan to connect to the adapters multiple displays, do not use an adapter-bridge. This scheme will allow you to expand the image on multiple displays
Install the drivers for the motherboard. Use the set of files and applications that activates the SLI (CrossFire) mode of operation of videoadapters.
Update the drivers for video cards. Launch the application and activate dual channel mode graphics accelerators. Configure the settings for the graphics cards. Disable unnecessary functions. Note that you will not be able to individually configure each charge. This means that both devices must be activated option.