Too much noise with volumetric lighting with a slow computer? Try and render out in a higher resolution with lower samples, and then scale it down afterwords! : r/blender
Too much noise in interior rendering - Lighting and Rendering - Blender Artists Community
Reducing Noise — Blender Manual
How to reduce noise, grain and fireflies in Blender cycles render
Simple technique to reduce noise on Cycles • Blender 3D Architect