20-30% improvement on a 10700K when CPU-limited.
Another 10-15% on a 4080 when GPU-limited.
It also brings DLSS (for some reason, I thought it was already in there), DLAA, Reflex, and Frame Generation.
The notes also state:
[PC Only] Add some GPU performance optimizations, which will be more impactful on higher end cards.
[PC Only] Improved renderer threading model, improving CPU usage most notably on higher end systems.
Various stability and performance improvements