In certain circumstances, the system will present the same frame to users even if changes may have been made to the underlying content of the frame. The most typical example is work-related activity involving static content in between the motions of a mouse or windows. Even when set to the lowest level, the screen is still refreshed many times. This is because the FreeSync technology lowers the refresh rate of each frame in synchrony with the monitor. This already results in a significant reduction in GPU consumption. In 2021, AMD started enabling a feature known as Panel Self Refresh (not based on proprietary technology). Intel and NVIDIA already supported this feature; however, AMD only started supporting PSR with DCN 3.1 and newer (AMD Rembrandt APU series).
In a nutshell, the PSR grants the panel the ability to locally refresh the idle pictures prior to the delivery of update frames. In the absence of PSR, new frame requests prohibit certain components of the graphics processor from powering down, which causes the components to consume more power than they would otherwise. AMD has been hard at work developing a new feature known as FreeSync Panel Replay to broaden their support for PSR. Recently, a patch for the AMD Linux display driver included the following description of this feature:
As was discussed, the feature of “frame replaying” would cut down on latency by maintaining source and transmitter synchronization; as a result, it would be much simpler to regulate the display’s refresh rate. In addition, by playing back the pixel data to the receiver, it is possible to reduce the amount of power drawn from the GPU because certain components of the GPU will no longer need to be powered on. As a result, the technology ought to be regarded as an advancement of PSR because it supports an increased number of instances and has a lower latency. On the other hand, it would no longer be compatible with PSR. On mobile platforms that currently support variable refresh rates and FreeSync, the FreeSync Panel Replay feature will find its place as a useful addition. On the other hand, it is not entirely clear whether this technology will only be available on AMD GPUs with DCN 3.1.4 or later.