DisplayPort (DP)

DisplayPort is a royalty-free standard created by the Video Electronic Standards Association (VESA). It is found on PCs rather than on TVs. DP:

• Can carry more than one stream of high-quality digital video and audio signals, but not Ethernet data.

• Supports resolutions as high as 8194 x 4320.

• Uses cables up to 35 feet that have 20 pin-connectors with locking mechanism.

• Has a Mini DisplayPort (MDP) version.

• Is compatible with High-Definition Multimedia Interface (HDMI), Digital Visual Interface (DVI), and most Mac devices.

HDMI

HDMI is a forward compatible standard developed and promoted by the consumer electronics industry. It is compatible with LCD monitors and most components in a modern entertainment system. HDMI:

• Can transmit a stream of high-definition digital video and up to 8 channels of audio signals.

• Supports up to 25-foot cable before degradation.

• Offers three types of HDMI used by consumers—each with 19 pins on each end of the cable.

  • Type A is the standard used on TVs, monitors, and 4K screens.

  • Type C is a miniHDMI used on video cameras.

  • Type D is a micro HDMI used on smartphones.

USB

The USB port is one of the most common computer ports for local communications. USB ports are used to connect a variety of devices:

• Mouse and keyboard devices

• External storage devices

• Digital cameras

• Printers

• Scanners

• Microphones

• Webcams

DVI

DVI is a popular connection to carry analog and digital through the same white video cable. DVI:

• DVI can transmit analog signal (DVI-A), or digital signal (DVI-D), or can integrate both (DVI-I).

• Single-link supports up to 1920 x 1200 resolution.

• Dual-link supports up to 2560 x 1600 resolution.

• Connectors may have up to 24 pins for digital signals, plus 4 pins for analog signals for single-link or dual-link connection.

• Cable is designed to perform optimally at 16 feet but good performance may extend to 30 feet.

• Backward compatibility with Video Graphics Array (VGA) (analog).

VGA (DE-15)

VGA is a blue serial connector that has been around for a long time. VGA connected external display devices such as CRT monitors, projectors, and some of the first models of LCD monitors. VGA:

• Transmits an analog video signal—no digital option.

• Has lower-quality displays with 640 x 480 resolution.

• Uses cables with 15 holes on one end and 15 pins on the other.

• Uses a DB-15 connector in three rows.

S-Video Mini Deutsches Institut für Normung-4 (miniDIN-4)

The Separated Video (s-video) port is used for connecting external displays. It has slightly better picture quality than a Radio Corporation of America (RCA) video port.

Audio Jack

Audio jacks are used to send or receive analog audio signals. Audio jacks use 3.5 mm Tip Ring Sleeve (TRS) connectors to connect audio devices such as:

• Speakers

• Headphones

• Microphones

• Audio output devices

Audio jacks use a common color code to denote the port type:

• Green: line out

• Pink: mic in

• Blue: line in

• Orange: subwoofer

• Black: rear speakers

Sony/Philips Digital Interface (S/PDIF)

Fiber S/PDIF

The S/PDIF port is used to send a digital audio signal to high-end audio devices such as home theater systems or Dolby Digital surround sound systems.

• Coaxial S/PDIF ports use a copper coaxial cable to transmit signals.

• Fiber S/PDIF ports use fiber optic cables to transmit signals.

Registered Jack-45 (RJ45)

RJ45 ports are used to create Ethernet networks by connecting multiple computers and networking devices. RJ45 ports have eight connector pins.

RJ11

RJ11 ports are used by telephones and modems to send analog signals. RJ11 ports have four connector pins.

Personal System/2 (PS/2)
(Mini-DIN-6)

The PS/2 port connects older PS/2 keyboard or mouse devices.

• PS/2 ports are color coded.

  • Purple denotes the keyboard port.

  • Green denotes the mouse port.

• Connector is called mini-DIN-6.

• The PS/2 port has been replaced by the USB port.

Serial (DB-9)

The serial port can connect many different serial devices such as a printer, barcode scanner, router, dial-up modem, or serial mouse.

Serial ports are commonly used to connect a console port or management port to configure and manage networking devices.

• Recommended Standard-232 (RS-232) is a standard for serial communication transmission of data. It defines the signals connecting computer equipment like a computer and a modem.

• The RS-232 standard was commonly used in computer serial ports. USB has replaced RS-232 for most of its peripheral interface roles.

• Many computers no longer come equipped with RS-232 ports.

• Often called DB-9 or DE-9. The connector gets its name from the D shape of the connector. The letters A, B, C, D, or E denote the shell size.

Parallel Data Bus-25 (DB-25)

The parallel port connects older devices that use a parallel interface, such as printers, hard drives, and gamepads.

• The parallel port was replaced by the USB and RJ45 port.

• Parallel port uses the D-sub connector with 25 pins.

DB-15

The DB-15 is a gaming port used by legacy game pads, joysticks, and MIDI devices.

• These ports are typically found on older sound cards.

• The DB connector with 15 pins in two rows is sometimes called DE-15 or DA-15.

Thunderbolt 3

Thunderbolt is the brand name of a hardware interface developed by Intel collaborating with Apple. It supplies power for connecting external displays to a computer.

• Thunderbolt combines Peripheral Component Interconnect Express (PCIe) and DisplayPort into two serial signals in a bi-directional channel of digital video, audio, DC power, and data signals up to 40 Gbps. It:

  • Uses active cables to achieve maximum data transfer rates.

  • Allows you to daisy chain up to seven devices off one port.

• Thunderbolt 1 & 2 have a mini DisplayPort (MDP) connector.

• Thunderbolt 3 standard USB-C has a lightning bolt icon and is royalty free to encourage OEMs and chip manufacturers to use it.

Lightning

Lightning (created by Apple) connects mobile devices like iPhones, iPads, and iPods to a host.

• Proprietary computer bus and power connector used to connect to host computers, monitors, cameras, chargers, or other peripherals.

• Small, symmetrical plug with 8 pins on either side.

Internal cable and connectors

SATA

SATA, also known as Serial ATA, is frequently used in modern computers to connect hard drives to the motherboard.

• A SATA data cable has 7-pin connectors. It also uses a separate power cable with a 15-pin connector.

• The cable connects to motherboard and one device.

• Cables can be a long as 1 meter.

• SATA3 cables can transfer up to 600 MB/s.

• Two connectors are available: straight or L-shaped.

• Connectors are keyed for proper connection.

• Cables are thin and flexible to help keep the system tidy.

Internal ribbon and 50-pin connector

SCSI

SCSI is usually found only in high-end servers, mainframe computers, and redundant array of independent discs (RAID) storage devices.

• SCSI has limited BIOS support. You can configure it for each computer.

• SCSI controller coordinates between all other devices on the host bus adapter (HBA).

• The controller can be built into the motherboard or on a card plugged into a slot.

SCSI Parallel Interface (SPI) uses a parallel bus. It's the earliest SCSI interface and has been around for over 20 years. The standards have been revised numerous times and it is still used today.

• Internal parallel SCSI ribbon cables usually have connectors with 50, 68, or 80 pins.

• SCSI ribbon cables can transfer up to 640 MBps.

• Different manufacturers' connectors are not compatible with one another.

SCSI interface can be confusing since implementation varies by manufacturer. The different interfaces are not compatible.

Internal cable and connector

SAS

SAS is a point-to-point interface that uses a serial protocol. It's typically found in enterprise-level storage systems like RAID, tape drives, or dedicated servers.

• SAS replaces parallel SCSI.

• SAS-4 throughput up to 22.5 Gbps, full duplex.

SAS is a serial protocol for SCSI commands.

Internal ribbon with 40-pin connector

IDE

IDE, also known as Parallel AT Attachment (PATA), is an older technology.

• IDE uses ribbon cable with 40-pin connector. It requires a separate Molex power cable. Red edge denotes pin 1.

• Cable connects to motherboard and two devices.

• Ribbon cable can be up to 18 inches long.

• IDE has mostly been replaced by SATA in newer PCs.

Male-to-female connector

Molex

Molex is a generalized name given to a common type of connector used to power internal computer components.

• Molex comes from the company name that pioneered the two-piece electrical connector.

• No single connector is technically called a Molex connector since Molex makes dozens of different connectors

• Molex became a standard connector in computers and other electronics.

• The 4-pin power connector (shown), Molex #8981 (red, black, black, yellow wires) is still used in many PCs to power IDE or SATA hard drives.

Male-to-male connectors

eSATA

eSATA creates a SATA connection in an external enclosure.

• External connections can be added using an expansion card.

• Connection is hot-swappable.

• eSATA has same fast SATA throughput.

• Devices require separate power connection.

• Multiple eSATA devices can be connected when port multiplication is supported.

Male-to-male 68-pin connectors

SCSI

SCSI connects other hardware: hard drives, tape drives, CD-ROMS, scanners, and printers.

• External SCSI devices attach to the adapter card.

• Multiple devices can be daisy chained using a cable and two connectors (shown).

• As many as 7 or 15 devices can be connected to a single channel. Terminate the last device.

• Different SCSI variations use different connectors usually with 50, 68, or 80 pins.

• Shielded molded cable with thumbscrew (shown).

SCSI interfaces can be confusing because SCSI types offered by different manufacturers have different speeds, bus widths, and connectors.

Small form factor (SFF)
SFF-to-SFF connectors

SAS

SAS cables support emerging data storage technologies. SAS:

• Uses SFF connectors.

• Is compatible with SATA drives that can be connected to an SAS controller.

• Has SAS-4 with throughput up to 22.5 Gbps, full duplex.

• Has a hot-pluggable connection.

• Uses expanders to daisy chain up to 65,535 devices. Terminate the last device.

Small form-factor pluggable (SFP)
with duplex optic cable

iSCSI

iSCSI is used to access enterprise-class storage systems by carrying SCSI commands over TCP/IP network.

• Fast, flexible; throughput up to 400 MBps.

• Needs initiator software to manage iSCSI connection.

• Can run over long distances using existing network infrastructure.

• Can be attached to network port, router, or switch.

• Uses hot-pluggable connections.

• Can connect to various types of devices depending on the gigabit interface converter (GBIC) module installed in the host adapter. For example, iSCSI host adapters for copper supports Fast Ethernet up to 400 MBps.

Fibre Channel over fibre-optic cable (shown)

• Connected with duplex fibre-optic cables.

• Uses SFP transceiver also known as Mini-GBIC.

• Offers throughput up to 200 MBps.

HDMI to DVI

Connects an HDMI cable to a DVI port.

VGA to DVI

Connects a VGA cable to a DVI port.

VGA to HDMI

Connects a VGA cable to an HDMI port.

DVI to Thunderbolt

Connects a DVI cable to a Thunderbolt port.

Ethernet to USB

Connects an RJ45 connector to a USB port.

Display connectors

Video cards have one or more connectors for attaching an external display. Always try to select a video card with connectors that match the display.

• Liquid-crystal display (LCD), light-emitting diode (LED), and organic light-emitting diode (OLED) monitors use one (or more) of the following connectors:

  • DisplayPort.

  • High-Definition Multimedia Interface (HDMI).

  • Universal Serial Bus-C (USB-C) ports connect newer monitors and video cards.

  • VirtualLink USB-C used for VR games

  • DVI are rarely used with new monitors.

  Most video cards have dual heads (two output connectors capable of displaying video simultaneously) and can support dual monitors. Some video cards now support 3,4,5 and 6 monitors.

  If necessary, you can use special cables to connect a video card to a monitor (e.g. USB-C to HDMI, DisplayPort to HDMI, and Mini-DisplayPort to HDMI).

Display quality

Both the video card and the external display determine the quality of images and animation. When selecting a video card, consider resolution and refresh rate.

• Resolution is the number of pixels displayed on screen.

  • A higher resolution means that more information can be shown on the screen.

  • A video card is rated by its max resolution. This is the highest possible resolution it can display (e.g., 1920 × 1080, 4096 × 2160, 2560 x 1440 and 5120 x 2880).

• Refresh rate is the number of times in one second that the GPU draws a frame.

  • Refresh rates are measured in hertz.

  • A refresh rate of 70 Hz or lower may cause eye fatigue.

  • An optimal refresh rate is between 75 Hz and 85 Hz. Today, some monitors have refresh rates of 120 Hz, 144 Hz, and even as high as 240 Hz.

  For optimal image quality and graphic performance, select a display (monitor or TV) that matches the video card specifications, and vice versa. Consider the intended use of the video card and display monitor. A good rule of thumb is the higher the resolution, the bigger the monitor should be.

Processing capabilities

The GPU handles all video rendering tasks. GPUs are much more efficient at processing graphic data than a traditional CPU.

• Video hardware acceleration refers to using the GPU to render graphics.

• You can use settings in the operating system to control how much video processing is offloaded to the GPU.

• GPUs clock speed is rated in MHz. A higher speed means better performance. You can overclock GPUs. Overclocking increases the GPUs processing speeds. While it increases the gaming experience, increased watts and heat can shorten the life of the card.

Memory

Dedicated video cards use high-speed memory to store graphic data. The amount of memory on the card affects performance as well as other characteristics.

• The amount of memory on a card can range from 1 to 24 GB.

• Dedicated video cards use the following types of memory:

  • Double Data Rate 3 (DDR3), DDR4 and DDR5 memory are similar to system memory. This type of memory is cheaper, but provides fewer performance features than special graphics memory.

  • Graphics DDR2 (GDDR2), GDDR3, GDDR5, GDDR5X, GDDR6 and GDDR6X are DDR memory specifically designed and optimized for graphical data. This memory is more expensive, but results in greater performance.

Bus type

Video cards must be compatible with the expansion slots on the motherboard. Common slot types used by video cards include the following:

• Peripheral Component Interconnect Express (PCIe) x16 is the most widely used today.

• PCI is not the same as PCIe. PCI is a parallel connection; PCIe is a high-speed serial connection.

• Accelerated Graphics Port (AGP) is rarely found and outdated.

Motherboards with integrated graphics embed the functionality with the buses (e.g., PCIe, AGP, or PCI) on the system.

Multi-GPUs

You can link video cards together. This allows you to share the graphic processing load between the two GPUs.

• Multi-GPU configurations are manufacturer-specific:

  • NVIDIA uses SLI (Scalable Link Interface).

  • AMD uses CrossFire.

• Video cards are linked using a special bridge clip or through software (depending on the implementation).

• The motherboard and each video card must use the same connection method (SLI or CrossFire).

• The motherboard must also have multiple PCIe x16 slots.

• In most cases, both video cards must be identical.

Some motherboards allow you to link an integrated graphics controller with a video card installed in the expansion slot; however, this offers a negligible performance boost.

HDMI audio

HDMI cables can carry both video and audio signals; however, most video cards send only a video signal. You can use the following techniques to send an audio signal through the video card:

• Audio pass-through connects an audio output cable to the video card. The video card combines the audio signal with the video signal for HDMI output. This option is often called HDTV out.

• A graphics card with an onboard audio processor can decode and process audio and send it out the HDMI port. This option is often referred to as onboard sound.

DirectX/Open Graphics Library
(OpenGL)

DirectX is a collection of application program interfaces (APIs) that improves graphic, animation, and multimedia creations.

• DirectX includes multiple components targeted to a different aspect of multimedia. For example, Direct3D is the 3D rendering component of DirectX.

• Applications (typically games) are written using features included in specific DirectX versions.

• To view content written to a specific DirectX version, the video card must also support that (or a higher) version.

OpenGL is an alternative standard to DirectX that is used by some applications. Most video cards support both DirectX and OpenGL.

High-Bandwidth Digital Content Protection
(HDCP)

HDCP is a method for protecting digital media. The purpose of HDCP is to prevent the interception and copying of protected data streams as they are sent from a playback device to a display device (e.g., from a DVD player to an HDTV).

• When playing protected content from a PC, the DVD player, video card, and display device must all support HDCP.

• If you plan to watch protected content on a PC or play protected content from a PC to an external TV, make sure the video card supports HDCP.