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Display Power Savings Technologies
Intel® Seamless Display Refresh Rate Switching Technology (Intel® SDRRS Technology) with eDP* Port
Intel® DRRS provides a mechanism where the monitor is placed in a slower refresh rate (the rate at which the display is updated). The system is smart enough to know that the user is not displaying either 3D or media like a movie where specific refresh rates are required. The technology is very useful in an environment such as a plane where the user is in battery mode doing E-mail, or other standard office applications. It is also useful where the user may be viewing web pages or social media sites while in battery mode.
Intel® Automatic Display Brightness
Intel® Automatic Display Brightness feature dynamically adjusts the back-light brightness based upon the current ambient light environment. This feature requires an additional sensor to be on the panel front. The sensor receives the changing ambient light conditions and sends the interrupts to the Intel Graphics driver. As per the change in Lux, (current ambient light luminance), the new back-light setting can be adjusted through BLC (Back Light Control). The converse applies for a brightly lit environment. Intel® Automatic Display Brightness increases the back-light setting.
The Smooth Brightness feature is the ability to make fine grained changes to the screen brightness. All Windows* 10 system that support brightness control are required to support Smooth Brightness control and it should be supporting 101 levels of brightness control. Apart from the Graphics driver changes, there may be few System BIOS changes required to make this feature functional.
Intel® Display Power Saving Technology (Intel® DPST) 7.0
The Intel® DPST technique achieves back-light power savings while maintaining a good visual experience. This is accomplished by adaptively enhancing the displayed image while decreasing the back-light brightness simultaneously. The goal of this technique is to provide equivalent end-user-perceived image quality at a decreased back-light power level.
- The original (input) image produced by the operating system or application is analyzed by the Intel® DPST subsystem. An interrupt to Intel® DPST software is generated whenever a meaningful change in the image attributes is detected. (A meaningful change is when the Intel® DPST software algorithm determines that enough brightness, contrast, or color change has occurred to the displaying images that the image enhancement and back-light control needs to be altered.)
- Intel® DPST subsystem applies an image-specific enhancement to increase image contrast, brightness, and other attributes.
- A corresponding decrease to the back-light brightness is applied simultaneously to produce an image with similar user-perceived quality (such as brightness) as the original image.
Intel® DPST 7.0 has improved power savings without adversely affecting the performance.
Panel Self-Refresh 2 (PSR 2)Panel Self-Refresh feature allows the Processor Graphics core to enter low-power state when the frame buffer content is not changing constantly. This feature is available on panels capable of supporting Panel Self-Refresh. Apart from being able to support, the eDP* panel should be eDP 1.4 compliant. PSR 2 adds partial frame updates and requires an eDP 1.4 compliant panel.
Low-Power Single Pipe (LPSP)
Low-power single pipe is a power conservation feature that helps save power by keeping the inactive pipes powered OFF. This feature is enabled only in a single display configuration without any scaling functionalities. This feature is supported from 4th Generation Intel® Core™ processor family onwards. LPSP is achieved by keeping a single pipe enabled during eDP* only with minimal display pipeline support. This feature is panel independent and works with any eDP panel (port A) in single display mode.
Intel® Smart 2D Display Technology (Intel® S2DDT)
Intel® S2DDT reduces display refresh memory traffic by reducing memory reads required for display refresh. Power consumption is reduced by less accesses to the IMC. Intel S2DDT is only enabled in single pipe mode.
Intel® S2DDT is most effective with:
- Display images well suited to compression, such as text windows, slide shows, and so on. Poor examples are 3D games.
- Static screens such as screens with significant portions of the background showing 2D applications, processor benchmarks, and so on, or conditions when the processor is idle. Poor examples are full-screen 3D games and benchmarks that flip the display image at or near display refresh rates.