LCD – For the Novice and the Expert

Monitor cables

We stressed how important it is to make sure that the VGA cable stays in good condition. Unfortunately, sometimes proper care isn’t enough. Choosing the right monitor cable also plays a critical role in your signal quality.

Trust us — you want to run DVI, if possible, all the time. (Check out the next section for more information on that debate.) Even though DVI cables are not immune to interference, analog connections often amplify the flaw and produce awful artifacts. With that in mind, you also should never buy cheap KVMs or VGA cables.

Click to enlarge.

A close-up of a good VGA cable versus a poor one. The good cable (upper) is much thicker due to its heavier insulation and also uses a heavy duty adaptor, which is much less likely to fail.

The DVI cable will typically produce a clean signal up to 25 feet. A 15 pin VGA cable will degrade signal after about 6 feet. Thus, as a rule of thumb, we always encourage our readers to buy the shortest cables available. How will you know if your cable is too long?

All analog cables present fundamental flaws in their design. The analog signal is very prone to harmonic and spontaneous interference. You do not want your VGA cable to run parallel to power cables or AC to DC converters. In fact, you really do not want any cables or metal touching your cable. We might be a little retentive, but we put a 2" plastic sheath (HomeDepot, 10 cents per foot) over our monitor cable when benchmarking monitors.

Have you ever kicked your monitor cable and the screen turned red? A worn cable will ground parts of the signal on the DVI or analog cable, resulting in off-color images. From time to time, I get asked from someone to fix their monitor, only to find it has a three inch gash in the cable.