DisplayPort is a digital display interface developed by the Video Electronics Standards Association (VESA) for connecting a video source to a display device. It is known for its high bandwidth and support for high resolutions, refresh rates, and color depths.
This blog post will compare DisplayPort 2.1 (DP 2.1) and DisplayPort 1.4 (DP 1.4), highlighting the key differences between these two versions to help you determine which one is right for you. These key differences include:
Bandwidth:
- DisplayPort 1.4: 32.4 Gbps
- DisplayPort 2.1: 80 Gbps
DisplayPort 2.1 offers nearly triple the bandwidth of DisplayPort 1.4, making it capable of supporting significantly higher resolutions and refresh rates.
Encoding:
- DisplayPort 1.4: 8b/10b encoding
- DisplayPort 2.1: 128b/132b encoding
The encoding scheme used by DisplayPort 2.1 is more efficient, allowing it to achieve higher data transfer rates with less overhead.
Concurrent LT for Multiple Repeaters:
- DisplayPort 1.4: Trains repeaters one at a time
- DisplayPort 2.1: Trains repeaters concurrently
This feature in DisplayPort 2.1 significantly reduces the time it takes to train multiple repeaters, which can be beneficial for long cable runs. See DisplayPort 128b132b Concurrent LTTPR Link Training for more details.
Forward Error Correction (FEC):
- DisplayPort 1.4: Optional
- DisplayPort 2.1: Mandatory
FEC helps to ensure the integrity of data transmission by correcting errors that may occur during the transmission process.
Panel Replay (PR):
- DisplayPort 1.4: Not supported
- DisplayPort 2.1: Supported
Panel Replay allows the display to store and replay static images, reducing power consumption.
Single Stream Transport (SST) and Multi-Stream Transport (MST):
- DisplayPort 1.4: SST is mandatory, MST is optional
- DisplayPort 2.1: MST is the default; SST is optional through falling back to DisplayPort 1.4 link rates
Multi-Stream Transport (MST) allows a single DisplayPort device, i.e., GPU, to drive multiple displays.
Aux-Less Advanced Link Power Management (ALPM):
- DisplayPort 1.4: Not supported
- DisplayPort 2.1: Supported
ALPM helps to reduce power consumption by allowing the DisplayPort link to be powered down during periods of inactivity.
Benefits of DisplayPort 2.1:
- Supports higher resolutions and refresh rates
- More efficient: 128b/132b encoding scheme more efficient vs 8b/10b encoding
- Better reliability: Forward Error Correction ensures data integrity
- Reduced power consumption: Panel Replay and ALPM features
Backward Compatibility:
- Both DisplayPort 2.1 and DisplayPort 1.4 are backward compatible with all previous versions of DisplayPort.
This table summarizes the key differences between DisplayPort P 1.4 and DisplayPort 2.1:
Cadence has a very mature Verification IP solution. Verification over many different configurations can be used with DisplayPort 2.1 and DisplayPort 1.4 designs, so you can choose the best version for your specific needs.
Learn more about Cadence’s Verification IP solutions.