Older, analog signals don't degrade as quickly as today's digital connections. This is why you might see 100-foot coaxial cables and incredibly long microphone cords. The thing is, they don't often have the bandwidth for uncompressed, high-resolution video and high-fidelity audio. Digital cables offer the opposite; they have the widest bandwidth capabilities but tend to break down over long distances.
First, a quick refresher on resolution and refresh rate: The default high definition resolution is 720p, or 1280 x 720. This is how most console video games are rendered natively before being upscaled to 1080p (or 1920 x 1080). Most television shows go over the air at 720p and most low-range and older HDTVs max out at 720p.
Reasonably newer televisions offer resolutions of 1080p and up. You can take advantage of this with Blu-Ray movies and computer video games (and a select handful of console games) as long as you're using the right cables.
60 hertz means that the screen refreshes its display 60 times in a second. 120 hertz means the screen refreshes twice as quickly. Televisions in the United States and Japan have refreshed at 60 hertz for a long, long time while 120 hertz is relatively new for consumer televisions. If you're doing 3D, 120 hertz is necessary. If you're watching 2D television, 120 is simply a nice, smooth bonus.
DVI
Let's talk about DVI. The DVI extender cable is used more for computers than for entertainment devices and doesn't carry with it any kind of audio signal, but it can offer resolution up to 2560 x 1600 at 60 hertz (or 3840 x 2400 at 33 hertz).
Be advised however, there are two different types of DVI cables with slightly different connectors: Single-link and Dual-link DVI. Single-link has, suspiciously, about half the bandwidth of Dual-link DVI and can't handle all the resolutions Dual-link can at the same refresh rates.
Fortunately, Single-link DVI has been mostly phased out and is rarely used in contemporary applications. DVI can typically extend up to 35 feet with proper shielding without any noticeable loss in quality. A DVI extender is useful to boost the signal and allow the joining of more cables to reach further terminals. DVI extenders may require external power to successfully boost the signal.
HDMI
HDMI carries a bit more video bandwidth and also has an audio stream for uncompressed high-fidelity audio alongside ludicrously high resolutions. The current top resolution for HDMI is 3840 x 2160 at 60 hertz as of September 4, 2013, thanks to the recently released HDMI 2.0.Of course, you'll need devices and a screen that support the newer spec, but HDMI devices released since 2006 support even 2560 x 1600.
HDMI cables can remain compliant and high-quality up to distances of 45 feet without a boost in the signal. Some manufacturers don't follow specification and compliance rules so strictly and have cables running as long as 100 feet or more, but at that length, you're likely to notice artifacting in your signal at the very least. Some cables won't be able to keep up the DRM handshake at that length.
If you're looking to run a cable over a long distance (or short distance!) without any loss in quality, you'll do a lot better with HDMI than DVI. It not only has a higher-resolution video stream, it also has a lossless audio stream that travels beside it. Add to that the number of devices that support HDMI and the shrinking number of those supporting DVI, HDMI is the only way to go.
Michael AlvarezAbout the Author:
Michael Alvarez has been working in the electronics and technology field for over 20 years. He enjoys sharing his knowledge and expertise of DVI extender with others; while continuing to grow his knowledge.