Adding a second monitor to an existing computer system can be done in one of two different ways. The more complicated but more powerful option is often to install a second dedicated graphics card inside the computer's case. This can also be done by replacing the existing graphics card with a unit that supports multiple monitors and has multiple output jacks already on it. Another way to add a second monitor to a computer is to use a USB adaptor that acts as a separate graphics card yet resides on the outside of the computer's case. Both of these options have positives and negatives associated with their use, and this article will attempt to explain them.
Option 1: Adding or Replacing The Graphics Card
All computers send the monitor's signal out through a special processor known as the GPU (Graphics Processing Unit). The GPU can either be integrated into the motherboard of the computer or it can reside on a separate AGP or PCI-e card that fits into a long thin socket on the motherboard. Once the user knows what type of card is able to be used with the computer (check your manual or read the specs online) a new card can be added to a empty slot. If the available slots are all full (perhaps with another graphics card) it may be necessary to purchase a multihead graphics card which will allow for two or more monitors to be connected to the same card.
Option 2: Using a USB Graphics Card
While using a dedicated graphics card installed on the motherboard is often the most powerful option available to a user, there are many companies that now offer USB based graphics cards that allow a computer to have many different monitors hooked up to it at the same time. Some, such as the new Lenovo DL-195 are powerful enough to provide 720p or even 1080p high definition output that can be displayed on an HDTV monitor.
