MST vs SST – DisplayPort Technology

DisplayPort is one of the latest and arguably one of the most effective display technologies on the market. When it comes to displays, most people are familiar with DisplayPort, or at a minimum its primary “competitor”, HDMI. Some familiar with the DisplayPort (regularly seen as DP) connection are still not aware that the configuration supports two separate transport modes. These are Single-Stream (SST) and Multi-Stream Transport (MST). 

SST (Single Stream Transport) mode – 

SST can only handle transmission to one downstream display through a single downstream port. However, a second screen can mirror other monitors. MacOS only supports DisplayPort SST mode.

Recently, 4K displays have started to use SST to eliminate the need to combine two halves of the display in software. Instead, SST monitors have scalers that support 4K resolutions at 60Hz in a single tile. 

MST (Multi Stream Transport) mode –

MST can handle transmission to multiple downstream displays through a single cable allowing you to stream independent video displays from a single desktop or laptop host. 

Designed for DisplayPort 1.2 or higher video output specifications, MST stitches two halves of a display together to combine into a large surface or “tile”. Due to the multi-signal carry from MST, a single cable allows for daisy-chaining, and hubs with multiple 4k monitor configurations.

With multi-monitor capability, the next important concept to understand is the difference between a cloned and an extended display. 

MST Docking Stations

Using a combination of USB-C DP Alt mode and the MST capabilities of DisplayPort MST Docking Stations allow for expansion of additional Displays and accessories.

The Difference Between Mirrored & Extended 

Cloned Display Mode simply duplicates the host desktop image onto your secondary or other additional monitors connected to the host.

Through Extended Display Mode, additional screen space can be added to your native laptop or desktop monitor through additional external displays, effectively expanding your maximum screen space. All displays can have different screen resolutions, refresh rates, and screen resolutions (landscape or portrait). Extended mode is the most widely used mode when it comes to MST setups.

What’s Daisy-chaining? 

Multi-Stream Transport also brought along the ability for “Daisy-chaining”, which describes your ability to connect a series of monitors together via a single DP connection between at least two independent devices. In practice, this looks like a host video output device such as your laptop connecting to a dock and/or to an additional second monitor. This second monitor then connects to a third. 

In short, instead of requiring a number of independent ports and cables, a single cable connection from monitor to monitor can extend the range of your screen to multiple displays with MST technology. Daisy-chaining is a distinguishing factor in DisplayPort due to the fact that HDMI is only capable of driving a single display per cable. 

For all of your DisplayPort connection needs, take a look at our collection of MST adapters and docks.