Learn about the Interactive Sampling Quality when raytracing in VRED.
Video captions: Open Render Settings and select the Raytracing Quality tab. Select Precomputed + Shadows from the Interactive and Stillframe menus. Activate Raytracing in the toolbar. Open the Lightsource Sampling Quality section. Increase Interactive quality up to 2. You can immediately see a less noisy result in your interactive window. Activate Statistics in the toolbar. You can now quality the usage tradeoff due to increasing interactive samples. Switch back to quality 1 and compare the difference in the Current FPS (frames per second). You can, thus, weigh up whether you want to work in a performance or quality-oriented way.