Graphic Card I/O Connectors and Interfaces

Nowadays, graphics cards can have many different connection ports suitable for different uses. Some are common, others optional and often it gets confusing. We are going to explain some of the Input/Output port differences here...

There are 2 electronics systems signals worldwide; Digital Signals and Analog Signals. Digital Signals are always preferred since they are less susceptible to noise than Analog and always easier to deal with.

Now, let’s talk about the different connectors:

VGA (Video Graphic Array)

Signal Type: Analog

Max. Resolution: 2048 x 1536 @ 85 Hz

Transmits Audio: No

This type of connector is one of the D-Sub (D-subminiature) or often called DE-15. That is why some people confuse between VGA and D-Sub . They think they are different. D-Sub has many connecters of various shapes and types. VGA connecter is one of them which is commonly used in computers. So if you are talking about computers, that means VGA = D-Sub.

It is mainly used to connect to external monitors. It was used on old graphic cards and weaker ones. It is also still available on nowadays laptops.

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S-Video (Separate Video)

Signal Type: Analog

Max. Resolution: 720 x 536 @ 50 Hz / 720 x 480 @ ~60 Hz

Transmits Audio: No

S-Video is one of the old video connecter that was introduced before DVI was introduced. It was common in laptops and some desktops. It is considered obsolete now and no longer used. It is also known as Y/C because the signal is carried onto two separate signals. "Y" is called lumen and "C" is called chroma.

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HDMI (High Definition Multimedia Interface)

Signal Type: Digital

Max. Resolution: 2560 x 1600 @ 75 Hz / 4096 x 2160 @ 24 Hz

Transmits Audio: Yes

HDMI is one of the newly introduced technologies and it’s very common among laptops, gaming consoles, HD Digital Televisions, DVD players and Blu-Ray players. It can also carry Audio signal along the line with various compressions like DTS, Dolby Digital and LPCM. The main advantages of this interface that the Video/Audio carried along is uncompressed, thus no quality lost while transferring Video/Audio providing superior Video quality and very pure Audio quality.

Since this interface is digital, every digital interface has an interface. The HDMI interface is called “TMDS” (Transition-minimized differential signaling). This protocol is also used in DVI interfaces and all digital communication interfaces. It also has a very high bitrate reaching 10.2 Gbit/s (340 MHz) by the new 1.4 Version.

Versions

Version 1.0 – 1.2a: This was the first versions introduced to the market. The maximum resolution since then was 1920 x 1200 @ 60 Hz (24-bit) with a bandwidth of 4.95 Gbits/s (165 MHz)

Versions 1.3: This version was a better one and along this version a newer highest resolution was introduced as 2560×1600 @ 75 Hz with a bandwidth of 10.2 Gbit/s (340 MHz) (24-bit) and 1920 x 1200 @ 60 Hz (48-bit). This version also has an updated list of CEC commands compared to the previous version.

Version 1.4: This version is considered the latest now supporting higher resolutions than Version 1.3 and supporting “3D over HDMI” technology. The new highest resolution is pumped to 4096 x 2160 @ 24 Hz with a bandwidth of 10.2 Gbit/s (340 MHz) (24-bit) and 1920 x 1200 @ 60 Hz (48-bit).         

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Display Port

Signal Type: Digital or Analog or Both

Max. Resolution: 2560 x 1600 @ 75 Hz

Transmits Audio: Yes

DisplayPort is the first display interface to rely on packetized data transmission (Packets of Digital Bit Steams of 0’s and 1’s) mostly, like Ethernet for Internet Data Transmission or USB for Data Transmission or Control Signals. DisplayPort is not like a DVI or HDMI and is not compatible with them unless it is a Dual Mode DisplayPort. Dual Mode DisplayPort ( DP) is exactly like a Single Link DVI or an HDMI using the same protocol “TMDS”. One Main advantage of the DP that it has more than double the bandwidth of HDMI at 21.6 Gbits/s (720 MHz). DisplayPort is currently available in Apple, Lenovo and HP systems and monitors. It is also available is some AMD/Nvidia Graphic cards as well as Home Theaters. There are to variants of Display Port, the normal one and a mini one (which is mainly used be Apple). 

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DVI (Digital Video Interface)

Signal Type: Digital or Analog or Both

Max. Resolution: Single Link: 1920 x 1200 @ 60 Hz / 3840 x 2400 @ 17 Hz

                            Dual Link: 2560 x 1600 @ 60 Hz / 3840 x 2400 @ 33 Hz

Transmits Audio: No

Digital Video Interface is a video interface standard designed to provide very high visual quality on digital display devices such as flat panel LCD computer displays and digital projectors. It is the recent connecter for nowadays graphic cards. Graphic Cards have up to 2 DVI connectors for Dual Display capability.

There are different variants of DVI like Mini-DVI and Micro-DVI which are mainly used on Apple MacBook computers.

There are 3 Types of DVI connectors:

* DVI-D is DVI connector which only carries Digital Signals where “D” stands for “Digital”.  

* DVI-I is DVI connector which can carry both Digital and Analog signals where “I” stands for “Integrated”.  

*DVI-A is less common and it can carry Analog Signals only.

Each of DVI-D and DVI-I has 2 types of Links, Signal Link and Dual Link. Dual Link should not be confused with Dual Display. Dual Link DVI connecters are used to allow resolutions up to 2560 x 1600 @ 60 Hz instead of 1920 x 1200 @ 60 Hz for a Single Link, by adding another Data Link (extra 6 pins in the middle), thus increasing the total bandwidth.

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