Cycles has just got a massive performance boost when rendering animations and re-rendering images thanks to Brecht Van Lommel's latest patch adding persistent data functionality to the render engine.
— Sebastian König (@s_koenig) April 5, 2021
Cycles previously had a "persistent images" functionality where images were loaded once when rendering an animation, but this new update allows for all unchanged data to be calculated only once, allowing for massive speedups in render times.
As a cherry on top of this already delicious cake, the speedups carry over to Eevee and workbench renders as well which automatically make use of this new caching technique.
— Daniel Zan Salazar (@ZanQdo) April 6, 2021
Get the latest Blender experimental build and experience the speed ups right away on the link below: