Render: faster animation and re-rendering with Persistent Data
For Cycles, when enabling the Persistent Data option, the full render data will be preserved from frame-to-frame in animation renders and between re-renders of the scene. This means that any modifier evaluation, BVH building, OpenGL vertex buffer uploads, etc, can be done only once for unchanged objects. This comes at an increased memory cost.
This just landed in 2.93 alpha today.