- Automatically chooses the amount threads to match the number of logical processors on your computer.
- Manually choose the amount threads to use for rendering. This can be useful for example, if you want to use your computer while rendering you can set the property to a thread count lower the amount of logical processors on your computer.
- Tile Order
- Order of rendering tiles. This does not significantly affect performance.
- Tile size X/Y
The size of the tiles for rendering.
Depending on what device you are using for rendering, different tile sizes can give faster renders. For CPU rendering smaller tiles sizes (like 32 x 32) tend to be faster, while for GPU rendering larger tile sizes give better performance (like 256 x 256).
- Progressive Refine
Instead of rendering each tile until it has finished every sample, refine the whole image progressively. Note that progressive rendering is slightly slower than tiled rendering, but time can be saved by manually stopping the render when the noise level is low enough.
For rendering animations it is best to disable this feature, as stopping a frame early is not possible.
- Save Buffers
- Saves all render layers and passes to the temp directory on a drive, and read them back after rendering has finished. This saves memory usage during rendering, particularly when using many render layers and passes.
- Viewport BVH Type
- Dynamic BVH
- Objects can be transformed, added and deleted interactively, at the cost of slower renders.
- Static BVH
- Object modifications require a complete BVH rebuild which reduces interactivity but renders faster.
- Start Resolution
- Resolution to start rendering preview at, progressively increase it to the full viewport size.
- Persistent Images
- Keep image data in memory after rendering, for faster re-renders at the cost of extra memory usage when performing other tasks in Blender.
- Use Spatial Splits
- Spatial splits improve rendering performance in scenes with a mix of large and small polygons. The downsides are longer BVH build times and slightly increased memory usage.
- Use Hair BVH
- Use a special type of BVH for rendering hair. The bounding boxes are not axis aligned allowing a spatially closer fit to the hair geometry. Disabling this option will reduce memory, at the cost of increasing hair render time.