About HDMI

HDMI cable and connector
Use with SMART products

Connecting to video and audio from computers and other inputs

Connecting to external displays

Maximum cable length

23' (7 m)

The High Definition Multimedia Interface (HDMI) is a type of cable and connection used for transferring digital data from an HDMI source device(such as a computer) to a display device(such as a monitor, projector, or television). HDMI combines video, Consumer Electronics Control (CEC), and multi-channel audio in a single cable, which reduces the cost and complexity of setup.

HDMI cables:

  • Support two-way communication

  • Are available in three sizes:

    • Standard (Type A)

    • Mini (Type C)

    • Micro (Type D)


    Most SMART products use the Standard (Type A) size.

  • Come in different types, each designed to meet a specific version of the HDMI standard


    Newer SMART Board interactive displays support premium high speed HDMI cables.

The following table provides more detailed information about the types of HDMI cables and the HDMI versions, resolutions, and refresh rates they support. Use this to determine the type of HDMI cable that will provide the best experience.

Cable type

HDMI version

Maximum supported resolution

Designed and certified for


HDMI 1.3

1920 × 1080 @ 60 Hz (Interlaced)

HD resolutions (720p and 1080i) used by older consumer electronics

High Speed (10.2 Gbps)

HDMI 1.4

3840 × 2160 @ 30 Hz

Ultra-high definition displays (for example, 4K UHD)

Premium High Speed (18 Gbps)

HDMI 2.0b

3840 × 2160 @ 60 Hz

Ultra-high definition displays (for example, 4K UHD) with advanced features, such as:

  • 4K UHD @ 60 Hz

  • HDR

  • 3D displays

  • Deep Color

Ultra High Speed (48 Gbps)

HDMI 2.1b

3840 × 2160 @ 120 Hz

7680 × 4320 @ 60Hz

Uncompressed 4K UHD at 120 Hz and 8K UHD @ 60 Hz video, HDR, VRR, eARC, and all other HDMI 2.1b features

Refer to a SMART product’s specifications to see which HDMI standards and resolutions it supports.

Cable selection checklist




For 4K UHD content, the cable is certified Premium High Speed HDMI (18 Gbps).

Look for the Premium High Speed HDMI cable certification label on the cable’s packaging. Cables with the label have been tested to enure quality for 4K UHD content.

For 8K UHD content, the cable is certified Ultra High Speed HDMI (48 Gbps).

Look for the Ultra High Speed HDMI cable certification label on the cable’s packaging. Cables with the label have been tested to enure quality for 8K UHD content.

About Display Port

Display Port cable and connector
Use with SMART products

Connecting to video and audio from computers and other input sources

Maximum cable length

23' (7 m)

Display Port is a high-bandwidth digital display interface mainly used for connecting a video source to a display device. Found mostly on computers and monitors, Display Port, like HDMI, also supports audio. Display Port was designed for modern displays, whereas HDMI was designed for consumer electronic connections, such as HDTVs, game consoles, and so on.

The Display Port interface can be transmitted over Display Port cables or over USB or Thunderbolt cables that have the USB Type-C connector.

Display Port cables:

  • Support resolutions beyond 8K UHD

  • Have standard and mini connector formats

  • Come in different versions (The current version is 2.1.)

  • Feature a captive/locking connector, which is useful for permanent installations

Cable selection checklist



The cable’s version is compatible with the devices it’s being connected to.

About DVI

DVI cable and connector
Use with SMART products

Connecting to video from computers and other inputs

Maximum cable length

23' (7 m)

Digital Visual Interface (DVI) is a video display interface used to connect a video source (such as a computer) and a display device (such as a monitor). DVI was designed as a digital replacement for the analog VGA connection.

If only one end of a connection uses DVI, you can use a converter to make the connections compatible.

The two most common versions of DVI connections are shown below.

DVI-D connector with less pins than a DVI-I connector

DVI‑D (dual link)

DVI-I connector with more pins than a DVI-D connector

DVI‑I (dual link)


Although DVI is typically a video-only connection, some audio source devices can use DVI to send audio. In this case, you must convert the DVI cable to an HDMI connection to connect it to the SMART product. Refer to the source device’s documentation to see if it supports DVI audio. Otherwise, if you need to include audio and other data, such as touch, you will need to use a connection other than DVI.

Cable selection checklist




The cable’s connector matches the device’s connector type.

Some connectors, such as DVI-D, work with digital equipment only. Other types of connector, such as DVI-I, can work with both analog and digital connections. Make sure you choose the correct type for the device.

About VGA

VGA cable and connector
Use with SMART products

Connecting to video from computer inputs

Maximum cable length

23' (7 m)

Video Graphics Array (VGA) is an analog interface designed for use with monitors and computers. VGA connectors are commonly found on older computers and equipment. VGA is no longer common.


  • Although a VGA connection can support up to 1080p with the right source device, this is not recommended. This use pushes the VGA standard to its upper limit. Unless both the cable and source device are of the highest quality, degradation in video quality is likely.

  • VGA is a video-only connection. If you need a setup to include audio and other data (such as touch), you’ll need to use other connection types that support those types of data.

Using low-quality, passive (non-powered) VGA cables can result in an unfocused image, ghosting, noise, rolling lines and other adverse effects.

Cable selection checklist




The cable’s connectors have all pins fully populated and wired.

VGA cable connectors have multiple pins. Lower-cost cables might not include them all, and this can cause operational issues.

The cable’s gauge size is appropriate for its required length.

When running a VGA cable less than 10' (3 m), a thinner cable (about 12–15 mm) will work. However, use a thicker cable if you need to run the cable 10'–23' (3–7 m). Consider using a cable that also has smaller ferrite beads on the ends.

The cable has a minimum of 95% overall braid shielding.

The cable’s shielding should be, at minimum, a 95% overall braid. Even better, use a double braid with good bonding on the shell. The braid should be either soldered or mechanically attached to maintain constant contact. In the absence of a specification from the manufacturer, you can only determine the degree of shielding through a destructive test of a cable sample.

About optical digital audio

S/PDIF cable and connector
Use with SMART products

Connecting to audio from computers and other inputs

Connecting to external speakers and other audio devices

Maximum cable length

As short as possible 1

Optical digital cables use plastic or glass fiber filaments, similar to fiber optics, that use light to transmit the signal. Although audio signals delivered by light don’t weaken as rapidly as they do with copper-wired cables, optical digital cables can be damaged by excessive twisting or curling. This risk increases when these cables run over longer distances. If possible, use a different type of connection if the cable run must be longer than 4'–6' (1.2–1.8 m).

The connector on an optical digital cable looks like a small square plug. This connector can come in a standard or mini size.


HDMI cables can also transmit digital audio, and HDMI cables with Ethernet also support digital audio return channels (ARC and eARC) from the display device in addition to the primary audio channel to the display device.

About analog audio

Stereo 3.5 mm cable and connector
Use with SMART products

Connecting to audio from computers and other inputs

Connecting to external speakers and other audio devices

Maximum cable length

20' (6 m) 2

Analog audio cables fall into a few categories:




An unbalanced cable features two or more conductors, one for ground and at least one for signal.

The stereo 3.5 mm cable is a commonly used unbalanced connection. It has a ground connection (sleeve), a connection for the right stereo channel (ring), and another for the left (tip).

3.5 millimeter connector tip with the tip, ring, and sleeve

Unbalanced connections are affordable and ideal for shorter connections. An unbalanced cable of good quality can provide a connection of up to 20' (6 m). The main disadvantage of an unbalanced cable is its susceptibility to electrical interference when using line levels.


Balanced cables use two conductors for the signal, one positive and one negative, in addition to the ground. This means a stereo application requires two cables.

Balanced connections are far more resistant to electrical interference and support runs of 98' (30 m). Longer runs have special considerations, and an engineer should be consulted. Although SMART products do not feature balanced audio connections, you can use a Balun device to convert unbalanced connections to balanced ones if you need to use a balanced cable. SMART does not sell or support Balun devices, but they can be used if implemented properly. Consult your reseller if you think the use of a balanced cable with a Balun device is required for your installation.


Powered connections can be balanced or unbalanced, and are only used to connect an amplifier to a speaker. Powered connections use a much heavier gauge of wire than standard connections, and the connectors will be larger than a standard connector as well. In addition, powered connections typically have a thicker, more durable jacket, enabling easier runs across floors, under stages, and so on.

Cable selection checklist




The cable has proper shielding.

An analog audio cable’s shielding is critical for ensuring the cable’s proper functioning. Make sure the cable has at least a 95% overall braided or foil shield. A hybrid shield of braid and foil is even better, and a double braided and foiled shield (not illustrated) is better still.

Audio cable with foil, braid, and jacket layers of shielding around the cable

The cable has a gauge size appropriate for its required length.

The thinner a cable’s gauge, the shorter its reach can be before signal quality is at risk. For example, if you need to run a 16' (5 m) stereo 3.5 mm cable, you should use a cable with a heavier gauge. The American Wire Gauge (AWG) standard indicates heavier gauges with a lower number and lighter/thinner gauges with a higher number.

The cable has the right gauge of wire.

When selecting analog audio cables, look for cables that have the right gauge of wire. If possible, use analog audio cables with a larger wire gauge for powered connections, such as connecting to speakers. The gauge should be at least 16 AWG, or 12–14 AWG for longer distances.

For unpowered balanced or unbalanced cables, the gauge should be at least 20 AWG.

Extending video cables

Use an active video extender that supports the correct video protocols if you need to extend a digital or analog video connection farther than the cables provided with the SMART product or if you need to extend the connection beyond 23' (7 m). An active extender will boost the signal integrity as the audio and video data is transmitted across longer distances.

Although high-quality passive cables can work at longer lengths, an active extender ensures satisfactory signal strength. The extender’s supplier should be able to recommend the length of cable that the extender can support.

Selecting video cable extenders

Use only active, externally-powered video cable extenders and not bus-powered extenders (that is, an extender that’s powered by the device it’s connected to).


SMART doesn’t support installations that use bus-powered video extenders. Before contacting SMART for assistance, replace any bus‑powered extenders with a shorter, passive (non‑powered) cable and test the system again.

Use only video cable extenders that meet the following requirements:




The video cable extender is from an established, reputable company.

SMART recommends you use products from well-established, reputable companies. SMART can not provide support for video extending beyond the supplied video cable.

The video cable extender supports the correct EDID and HDCP versions for the products being connected.

If you use a Video Distribution Amplifier (VDA) to extend an analog connection, make sure the VDA extender has an output connector that supports Extended Display Identification Data (EDID) and High‑Bandwidth Digital Content Protection (HDCP) data to pass through to the input.