Your computer may come with a monitor and the graphics card built in, but if you have multiple displays or want to use an older monitor with higher resolutions, then it could be time to buy a graphics card.
How do choose one?
There are two ways of connecting your monitor to your computer. Either via DVI (Digital Visual Interface), HDMI (High-Definition Multimedia Interface) or VGA (Video Graphics Array) connection. All three will allow you to plug your monitor directly into the graphics card without any further connections.
This is ideal if you play games on high settings, watch movies at full resolution or use extra large screen resolutions on your picture or editing software. It also makes them very easy and quick to install.
Can connect my old monitor to a graphics card?
If your monitor uses an analog connection, you can still use it with a graphics card by getting an adapter that converts the connection type of the monitor to match the graphics card. This is known as “digital-to-analog conversion”.
If your graphics card does not come bundled with a DVI or HDMI connector you can also use a separate cable for this too, although these will only convert the analog signal to digital rather than also converting from one connector type to another.
if don’t need multiple displays?
Your graphics card most likely comes with one HDMI and/or DVI connector on it and some have more than one. You can always use these connectors to plug your monitor into the graphics card if you only have one screen that you’re using with it.
However, if you need extra ports or wish to plug in a second screen that’s not digital (for example an older analog VGA display) then you’ll need to get a separate graphics card and video output box for each monitor. These boxes will allow the non-digital monitors to connect to them and the cables from them can then be connected to the graphics cards as normal.
If you plug your monitor into your graphics card, then when that card is not involved in a 3D rendering activity, it will be off. So if you’re using a laptop and have two cards (say for SLI/Crossfire) then alot of time one of them will be idle and so the monitor will just show blackness – about 50% of the time. If you want to see what’s happening on screen at any particular time then chances are this second Graphics card can’t display video output via DVI/HDMI because it is inactive. The better option would be to run a cable from the motherboard to your LCD Panel. Or alternatively use one of those cheap ‘optimizer’ dongles.
Now, how to get the signal from your MB?
There are various ways of doing this. First off – you could just use an S-Video cable that is built into most video cards. These have been around for years and are still quite prevalent in cheaper machines. If that doesn’t work then it depends on what port(s) your motherboard supports (e.g, some old Pentium D motherboards only had a VGA out). Look for a ‘Digital’ or other ‘non analog’ output on your motherboard’s ports page –
if you see one then all you need is an adapter to convert either HDMI or DVI -> Digital RGB + Sync. So any broken LCD monitor should do the trick. The following image should help.
On the left hand side, you have a few ports for connecting your PC to an HDTV (DVI/HDMI) and on the right are some different connection types available from a graphics card.
If you can’t find a non-DVI monitor then get one of these ‘optimizer’ boxes or a DVI -> VGA cable from Newegg and either connect it to the back of your graphics card via its DVI port or if its not digital then get a DVI->VGA dongle off of Newegg.
All of these generally use component cables which are RGB + Sync rather than VGA. The Sync is a separate wire to the rest (see image above) and is used by modern monitors for things like FL/FR.
If you do find yourself using one of these boxes then make sure it has an S-Video output too, otherwise get hold of a cheap RCA -> S Video cable and connect that instead – this will help your graphics card save energy because not all LCD panels support digital signals at 60Hz without horizontal lines flashing across the screen every few seconds