The DLSS programming guide for super resolution states the following in the section on dynamic resolution:
Not all combination of PerfQuality mode, resolution and ray tracing, support dynamic
resolution. Additionally, the Preset chosen for the initial range will persist across the lifetime of
the feature (presets will not vary even if scaling ratio varies). When dynamic resolution is not
supported, the call to NGX_DLSS_GET_OPTIMAL_SETTINGS returns the same values for both
the minimum and maximum render resolutions. This is also the case for older DLSS libraries that
did not support dynamic resolution.
From experimenting with the DLSS 3.5 SDK, I’ve determined that DRS is supported for scaling factors between 1/2 and 1.0 (for example, inputs between 1080p and 2160p are accepted when the requested output resolution is 2160p).
If the scaling factor is lower than 1/2, DRS is not supported, and the same min and max values are returned as described by the quoted paragraph. So, for example, the 1/3 scaling factor used by Ultra Performance mode causes DRS to be disabled.
What is the meaning behind this limitation? Is there a chance it will be lifted in the future? It seems like DRS should be supported for scaling factors between 1/3 and 1.0. This limitation prevents me from using DRS in scenarios where I need Ultra Performance levels of scaling, forcing me to lock the internal resolution at the 1/3 scale, when what I really want is for 1/3 to just be the lower bound.