Cycles Boost is a collection of render profiles and settings for Blender, built to give faster renders on RTX, GTX and CPU hardware. Its centerpiece is a redesigned Cycles Boost AI with Normal, Ultra and Extreme settings, paired with the original denoiser from Blender.
The set covers several render paths. There are CUDA profiles in Low, Medium and High tiers, CPU-only profiles for AMD and Intel that include an Optimal plus Intel Denoise option, and Optix AI profiles optimized for RTX GPUs. Eevee profiles are also included at Low, Medium and High. Stated optimizations include CUDA Branched Path Tracing, Optix speed-ups of up to 8 times, and volumetrics up to 10 times quicker. An update added a Lens Dirt Node for the Optix profiles.
Cycles Boost lists compatibility with Blender from 2.9 through 4.4, with updates that extended support to newer releases over time. Documentation covering installation is available, and a demo video comparing it with other render options is on the developer's page.