The specification defines multiple data rates. While eDP 1.3 topped out at HBR2 (5.4 Gbps per lane), eDP 1.4 fully standardizes support for HBR3 (8.1 Gbps per lane). With 4 lanes, eDP 1.4 can support up to of raw bandwidth. This is sufficient for 5K (5120 x 2880) displays at 60Hz or 4K at 120Hz without compression.
eDP 1.4 refines this with "Selective Update" capability. If only a small part of the screen changes (like a flashing text cursor or a small clock widget), the GPU only transmits the specific pixels that changed, keeping the rest of the link asleep. 2. Advanced Link Power Management (ALPM)
Silas looked at the oscilloscope trace. The firmware team, desperate to shave milliseconds off the boot time to impress the marketing department, had set the delay to 50ms. They had cut the specification in half. edp 1.4 specification pdf
The official eDP 1.4 standard and many other VESA specifications are available for free. You can download them directly from the VESA website at vesa.org or from the DisplayPort website at displayport.org . The VESA website is an excellent resource for staying up-to-date on the latest display standards, including the latest eDP 1.5.
eDP 1.4a Specification Overview | PDF | Hdmi | Computing - Scribd The specification defines multiple data rates
The eDP 1.4 specification was released by VESA as the successor to eDP 1.3. It was explicitly designed to accommodate the industry's shift toward higher display resolutions (such as 4K Ultra HD and beyond), faster refresh rates (120Hz to 240Hz), and wider color gamuts, all while drastically lowering system power consumption.
To understand eDP 1.4, one must first understand its parent protocol, DisplayPort (DP). While the standard DisplayPort was designed for external monitor connections, it wasn't perfectly optimized for internal device displays. , providing a streamlined, power-efficient, and high-bandwidth interface for connecting a system's graphics processor to its built-in panel. This is sufficient for 5K (5120 x 2880)
: Utilizing the HBR3 (High Bit Rate 3) link rate, it supports up to 8.1 Gbps per lane. With four lanes, it provides a total theoretical bandwidth of 32.4 Gbps (25.92 Gbps effective payload). This allows for: 8K resolution at 60Hz. 4K UHD at 120Hz with 10-bit color. 5K resolution at 60Hz with 30-bit color.
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: eDP 1.4 was a major leap forward in power optimization, helping to define the standard for energy-efficient displays.
| Feature | Description & Benefit | | :--- | :--- | | | Doubles per-lane data rate from 5.4 Gbps (HBR2) to 8.1 Gbps , achieving a total raw bandwidth of 32.4 Gbps. This is the foundation for supporting 4K, 5K, and 8K displays at high refresh rates. | | Panel Self Refresh (PSR) with Partial-Frame Updates | Allows the panel to refresh from its own frame buffer when the displayed image is static. Partial-frame updates refine this, updating only the portion of the screen that changes, dramatically reducing power consumption for everyday tasks like reading or idle desktop use. | | Display Stream Compression (DSC) 1.2 | A visually lossless compression standard that reduces the data needed for high-resolution video. This enables 8K displays and High Dynamic Range (HDR) content without requiring an exponential increase in bandwidth or physical lanes. | | Segmented Panel Displays with Multi-SST Operation (MSO) | Enables a new generation of thin, lightweight, and low-cost displays by supporting complex panel architectures. MSO can power multiple independent segments of a single physical screen, like those found in some foldable or unique form-factor devices. | | Regional Backlight Control | Zoning technology that controls LED backlight brightness for specific display areas in real-time. This is a cornerstone of High Dynamic Range (HDR) , dramatically boosting contrast ratios and perceived image quality while saving power. | | Expanded Link Rate Options & Lower Voltage | Introduces multiple new intermediate data rates between 1.62 Gbps and 8.1 Gbps, allowing systems to select a "just-right" speed to minimize power draw. Lower interface voltage swings also contribute to significant power savings. |