The Optix backend for Cycle is currently experimental and lacks some features.
- Baking support
- Branched path tracing (feature might be removed entirely and replaced with more options for regular path tracing)
- Using CPU memory for rendering
- Dynamic compilation of CUDA / Optix kernels
- CPU + GPU rendering
- Shader raytracing for AO and bevel
There are also a number of bugs and more urgent issues to solve for 2.81: T69801: Cycles Optix tasks for 2.81
With some further refactoring we could share more code with the CUDA and possibly other backends. Particularly for denoising and using CPU memory, as well as the split kernel organization.