VIDEO CONNECTOR GUIDE (1080P, 3D, 120Hz, 4K)
I've been lots of questions on different video connectors and what all do. There are also an increasing number of people who are gaming on 3D display, 120Hz display and 3D TVs who don't understand what cables they should be using. So here's a guide on the different cable types and what they are used for. I am omitting analog cables (VGA, component, etc) because they are deprecated, inferior, and you shouldn't be using them.
*Most of this knowledge comes from reading Wikipedia and various blog posts and by no means is a full and technically accurate description of cabling*
If there is anything incorrect or missing please PM me so I can update this guide. This guide is geared towards gamers and enthusiasts, HTPC guys this is not in depth enough for you.
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Terms
Refresh Rate (Hertz)
This a term that is very important to displays and their associated cables and connectors. The refresh rate of a display is how often an picture is drawn on the screen. This is measured in Hertz which is the number of cycles per second. For gamers the holy grail of performance is frames per second, this is closely related to refresh rate. Frames per second is the number of pictures a computer generates for display and the refresh rate is how often a picture can be updated with the frames generated.
Interlaced/Progressive Scan
You will often see p appended to resolution sizes which indicates a progressive scan resolution. A display does not draw all the pixels on your screen at once, it draws them by lines one by one top to bottom. Progressive scan is the normal way of drawing an image by drawing line 1 then line 2 and so on. In bandwidth constrained display technology there is an inferior and alternate method called interlaced. This effectively halves the required bandwidth by alternating which lines it draws, e.g. all the odd lines first then all the even lines.
120Hz Monitors
mkenyons new favourite baby. 120Hz monitors are gaining popularity among gamers by providing a faster refresh rate. Increasing the refresh rate to 120Hz moves it past what the normal human is capable of seeing making the image fliud and consistent and eliminating issues with image tearing and reducing monitor response times. Although current 120Hz displays do not have good colour accuracy and are expensive they are very popular and will eventually became mainstream for gamers.
Digital Video Interface(DVI)
DVI-I (Single Link)
DVI integrated connector. This supports both DVI output and analog output to VGA via a passive adapter. The DVI connector only supports single link connections, see below for details.
DVI-I (Dual Link)
DVI integrated connector. This supports both DVI output and analog output to VGA via a passive adapter. This is the most common output for GPUs. This DVI connector supports dual link with a dual link DVI cable, see below for details.
DVI-D (Single Link)
DVI Digital connector. This only supports DVI output and will not work with VGA adapter. This is a common input connector for regular 1080p monitors.
DVI-D (Dual Link)
DVI Digital connector. This only supports DVI output and will not work with VGA adapter. This is a common input connector for 120Hz/3D 1080p monitors and 2560x1600 monitors.
DVI-A
DVI Analog. This only supports VGA output through adapter. It is very uncommon to see this connector.
Single-Link vs Dual-Link
There are two broad groups of DVI connectors, single link and dual link. Dual link connectors and there matching cables effectively double the bandwith of single link cables. This allow them to carry either twice as many pixels for high resolution displays or deliver the images twice as fast for 120Hz or 3D monitors.
A single link cable will work with a dual link port but a dual link cable WILL NOT work with a single link port.
A dual link cable and port are required for 120Hz, 3D and 2560x1600 resolutions
Limitations
Single-Link = 1920x1200 at 60Hz max
Dual-Link = 2560x1600 at 60Hz or 1920x1200 at 120Hz (as a general guideline, the actually limitations are complicated)
Example display modes (single link):
- 1,920 × 1,080 @ 60 Hz
- 1,600 × 1,200 @ 60 Hz
- 1,920 × 1,200 @ 60 Hz
- 1440 × 900 @ 60 Hz
Example display modes (dual link):
- 2,048 × 1,536 @ 75 Hz
- 1,920 × 1,080 @ 120 Hz
- 1,920 × 1,080 @ 60 Hz 3D
- 1,920 × 1,200 @ 120 Hz
- 1,920 × 1,200 @ 60 Hz 3D
- 2,560 × 1,600 @ 60 Hz
- 2,560 × 1,600 @ 60 Hz
- 3,840 × 2,400 @ 33 Hz
HDMI
High Definition Multimedia interface was created using the same electrical signaling as single link DVI-Digitial with integrated audio. HDMI has evolved through various specifications over the years adding new features and unfortunately confusing consumer by introducing two different types of cables.
Versions
Version 1.0-1.2
The first implementation of HDMI which support up to 1920x1080 progressive scan video at 60Hz. In addition to this HDMI added CEC commands to allow control of consumer devices over HDMI
Version 1.3
This version of HDMI added bit streaming of audio for external decoding of DTS-HD Master Audio and DolbyTrueHD audio. It also added new colour space options and new CEC updates. At this point HDMI also specified too types of cables, category 1 and category 2. See below for more details
Version 1.4
This version greatly changed the HDMI specifications by increasing resolution support to 3840x2160 at 30Hz (Quad HD) and 4096x2160 at 24Hz (4K resolution). They also added Ethernet over HDMI, 3D over HDMI and the new micro HDMI connector.
Pre-Version 1.3
These cables support 1080p at 60Hz and may or may not work with version 1.3 specifications of bitstreaming and increased colour space.
Category 1 (Marketed as Standard Cables after Version 1.3)
These cables support 1080i or 720p at 60Hz
Category 2 (Marketed as High Speed Cables after Version 1.3)
These cables support 1080p, 4K, 3D and full colour space
Many of you have 3D TVs and would like to use them for gaming. This section explains the limitations of HDMI 3D versus Dual-Link DVI and DisplayPort solutions. 3D support is fully supported by HDMI but it is not as high performance as other implementations. In order to display 3D the screen and source device need to display two distinct images to each eye to trick you into seeing 3D. In order to do that twice as much information needs to be display at the same time compared to a 2D image. The maximum specifications of HDMI did not have this in mind and were set at 1080p60Hz. In order to show 3D your TV needs to display two 1080P images at half the normal speed to each eye giving you effectively a 1080p30Hz image. This is different then DVI and DisplayPort 3D which can display 1080p120Hz or 1080p60Hz in 3D. For movie content this isn't an issue as 30Hz is more than movies normally show at (24Hz) but in fast paced gamin it is not ideal. Be aware of this if you are interested in 3D over HDMI.
Example Display Modes
480p @ 60Hz
720p @ 60Hz
1080p @ 60Hz
1080p @ 30Hz 3D (High Speed HDMI v1.4)
4096p @ 24Hz (High Speed HDMI v1.4)
DisplayPort
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Taking a break will finish up later. mkenyon before I write the displayport section are they're any advantages/disadvantages/hiccups you've seen in using them with your 120Hz monitors?
(Samsung LE32A656) ... this is what it looks like now (desks are in a 90 degree setup)
