If you'd like to know the simplest way to hook up two monitors to your PC, you've come to the right place. Most often it's easier than you'd think. At least it is, when you have all the necessary pieces of hardware to make it work. This article walks you through what connectors you need, and what workarounds are available if you ever find yourself longing for more.
The Bare Minimum
If you have a laptop, chances are you already have the necessary ports to hook up a second monitor. All you need to do is to match the existing video-out to what's on the external display. If DVI is available on your external display you'll find it the simplest of things to convert whatever your laptop has to it. Converter cables are available at around in major online stores, such as Amazon.
All popular Linux distributions, all versions of OS X and Windows XP or later are capable of stretching, cloning or extending your desktop to multiple displays. Once you connect your display to the VGA, DVI or HDMI port on your laptop, it should power up and the OS of your choice should greet you with the preferences window. That's where you set the right resolution and refresh rate, in case it's not picked up by your OS instantly.
If, however, you're using a desktop computer, you need to double-check that it's got at least two signal outputs on the video card. Some VGAs have more than two connectors, but it seldom means that you can use them all for a separate display. Usually, you can use any two to feed two monitors, or one monitor and a TV.
AMD Eyefinity video cards come with six video outputs, of which you can use any number simultaneously, which, unfortunately, is unique to this model line.
What if There are Too Few Connectors
Desktop PCs tend to have at least two connectors. If not, you can add a second video card through a PCI-E slot. If it's an older computer with an AGP port, you still have possibilities, even though the motherboard does not facilitate multiple video cards.
The same solution provides itself when you want to use two additional external monitors on a laptop, which has only one port.
You can either use other laptops and computers to act as your virtual monitor, or can use a USB video card. Virtual monitors are great when you have a few old computers laying around without any purposeful use.
On a Windows PC you can use MaxiVista to route video data through your local network and make --up to four-- separate computers or laptops act as if they were monitors connected directly to your main system. The integration is rather tight but is limited to 2D applications, and require a small amount of CPU power to process the data stream.
Your second option, the USB video card, on the other hand allows you to fit any computer with external monitors regardless of available ports. Every computer worth its salt comes with at least one USB slot and a port for video-out. By using a USB VGA, you can make those two outputs the only two you'll ever need to drive external displays.
Always add the maximum number of monitors to the main system, if you can, and expand the workspace through virtual monitors and USB video cards later. This way you achieve the best support for hardware accelerated content, like games or CAD software.
MaxiVista costs in the range of , and each USB to VGA/DVI/HDMI adapter sets you back by about the same amount.
Conclusion
As with every multi-monitor setup, follow ergonomic and safety guidelines to ensure the best experience and minimize the risk of strain on the eyes and your back. Try to stick with displays from the same manufacturer, and same model whenever possible. It simplifies the setup process considerably, and gives you a consistent brightness, color representation and contrast throughout all your displays.
Most laptops will let you use the internal screen and one more. Most desktop PCs can already support two external monitors. If they don't, you can add more video cards, either through an internal port in case of the desktop PC, or through the USB port on laptops.
