The DVI cable standard is one of the most confusing
"standards" on the market today. DVI (digital Video Interface) DVI
comes in 5 different flavors. Some DVI connections (digital) are compatible
with HDMI. Some are compatible with VGA.
If your SOURCE has this connection:
Ex: Cable box, satellite box, PC, or laptop video card
And your MONITOR, TV, or PROJECTOR has this connection:
Cable Required for connection:
(Click link to view our products)
This is the most common DVI connection found on 99% of cable and
satellite boxes.
* - Most of My Cable Marts "DVI to DVI" cables are "dual
link". They are suitable for any DVI-D type connection - either single or
dual link.mpare our 2
** - DVI-D to HDMI are
always "Single Link" as the HDMI specification is only "Single Link"
WHAT IS DVI?
DVI stands for (D)igital (V)ideo (I)nterface.
DVI is a popular form of video interface technology made to maximize the quality
of flat panel LCD monitors and modern video graphics cards. It is a replacement
for the P&D Plug & Display standard, and a step up from the digital-only DFP
format for older flat panels. DVI cables are becoming increasingly popular with
video card manufacturers, and most cards nowadays include both a VGA and a DVI
output port.
In addition to being used as the standard computer interface, the DVI standard
was, for a short while, the digital transfer method of choice for HDTV, EDTV,
Plasma Display, and other ultra-high-end video displays for TV, movies, and
DVDs. Likewise, even a few top-end DVD players have featured DVI outputs in
addition to the high-quality analog Component Video. The digital market is now
swinging towards the HDMI interface for high-definition media delivery, and DVI
is being again constrained to the computer market.
WHAT ARE THE DVI FORMATS ?
There are three types of DVI connections: DVI-Digital, DVI-Analog, and DVI-Integrated
(Digital & Analog):
DVI-D - True Digital Video DVI-D cables are used for direct digital connections between source
video (namely, video cards) and digital LCD (or rare CRT) monitors. This
provides a faster, higher-quality image than with analog, due to the nature
of the digital format. All video cards initially produce a digital video
signal, which is converted into analog at the VGA output. The analog signal
travels to the monitor and is re-converted back into a digital signal. DVI-D
eliminates the analog conversion process and improves the connection between
source and display.
DVI-A - High-Res Analog DVI-A cables are used to carry a DVI signal to an analog display, such
as a CRT monitor or budget LCD. The most common use of DVI-A is connecting
to a VGA device, since DVI-A and VGA carry the same signal. There is some
quality loss involved in the digital to analog conversion, which is why a
digital signal is recommended whenever possible.
DVI-I - The Best of Both Worlds DVI-I cables are integrated cables which are capable of transmitting
either a digital-to-digital signal or an analog-to-analog signal. This makes
it a more versatile cable, being usable in either digital or analog
situations. Like any other format, DVI digital and analog formats are
non-interchangeable. This means that a DVI-D cable will not work on an
analog system, nor a DVI-A on a digital system. To connect an analog source
to a digital display, you'll need a VGA to DVI-D electronic convertor; to
connect a digital output to an analog monitor, you'll need to use a DVI-D to
VGA convertor.
WHAT ARE SINGLE AND DUAL LINKS ?
The Digital formats are available in DVI-D Single-Link and Dual-Link as well as
DVI-I Single-Link and Dual-Link format connectors. These DVI cables send
information using a digital information format called TMDS (transition minimized
differential signaling). Single link cables use one TMDS 165Mhz transmitter,
while dual links use two. The dual link DVI pins effectively double the power of
transmission and provide an increase of speed and signal quality; i.e. a DVI
single link 60-Hz LCD can display a resolution of 1920 x 1200, while a DVI dual
link can display a resolution of 2560 x 1600.
HOW FAR IS THE DVI MAXIMUM LENGTH?
The official DVI specification mandates that all DVI equipment must maintain a
signal at 5 meters (16 feet) in length. But many manufacturers are putting out
much stronger cards and bigger monitors, so the maximum length possible is never
exact.
Although the mandated DVI spec is 5 meters, we do carry cables up to 25 feet,
and have successfully extended them even longer than that (although results do
vary depending on hardware). For guaranteed signal quality on long runs, you
should consider using a powered DVI signal booster.
Despite common belief, there is such thing as signal loss in digital pictures.
When a DVI run is unstable, you may see artifacts and "stuck" pixels on your
display; further degradation tends to flicker out or shake, and the ultimate
sign of loss is a blank display. In-house tests on varying equipment have
produced strong signals up to 9 and 10 meters long. Tests at 12 meters generally
resulted in signal loss and an unusable image on the display, and anything
longer rendered no image at all.
Keep in mind that when using DVI-I cables at extensive lengths, you may not be
seeing a digitally-clear image on your screen. Because analog has a much longer
run, your display may auto-switch once the digital signal is too weak. For this
reason, long runs are best done with VGA (for analog) or HDMI (for digital). If
you have no option other than DVI, make sure you're getting the best image by
using DVI-D cables and verifying that your display is set to digital input.
HOW DO I KNOW WHICH CABLE TO USE?
Determining which type of DVI cable to use for your products is critical in
getting the right cable the first time. Check both of the female DVI plugs to
determine what signals they are compatible with.
If one or both connections are DVI-D,
you need a DVI-D cable.
If one or both connections are DVI-A,
you need a DVI-A cable.
If one connection is DVI and the other
is VGA, and the DVI is analog-compatible, you need a DVI to VGA cable or a
DVI/VGA adaptor.
If both connections are DVI-I, you may
use any DVI cable, but a DVI-I cable is recommended.
If one connection is analog and the
other connection is digital, there is no way to connect them with a single
cable. You'll have to use an electronic convertor box, available in either
analog VGA to digital DVI or digital DVI to analog VGA.
HOW TO RECOGNIZE A DVI CABLE?
There are two variables in every DVI connector, and each represents one
characteristic.
The flat pin on one side denotes whether the cable is digital or analog:
A flat pin with four surrounding pins
is either DVI-I or DVI-A
A flat pin alone denotes DVI-D
The pinsets vary depending on whether
the cable is single-link, dual-link, or analog:
Two separated 9-pin sets (rows of 6)
for a single-link cable
A solid 24-pin set (rows of 8) for a
dual-link cable
