Warning Num Samples Per Thread Reduced To 32768 Rendering Might Be Slower

In modern GPU rendering, the work of calculating light paths (samples) is divided among many parallel execution threads. Each thread is responsible for a certain number of samples before the results are combined into the final image. The "num samples per thread" parameter defines that batch size.

If you notice a significant slowdown or want to clear the warning, try these optimization steps: Switch to Progressive Mode Progressive Image Sampler

: Close other VRAM-heavy applications (like web browsers or other 3D software) to free up memory for the renderer. In modern GPU rendering, the work of calculating

The countdown typically looks like this in your V-Ray log window:

) is often a technical limit or "fallback" value used by developers when memory is constrained. How to Fix or Optimize If you notice a significant slowdown or want

: Excessive use of displacement maps, high-resolution textures (8K+), or V-Ray Fur. SketchUp Community Recommended Actions

A: You can suppress console output (e.g., run Blender with --log-level 0 ), but the performance effect remains. It’s better to address the root cause. SketchUp Community Recommended Actions A: You can suppress

When Arnold is forced to reduce samples per thread, it has to break the work into more "passes" or chunks. This creates overhead. Instead of finishing a pixel in one clean sweep, the engine manages more sub-tasks, leading to longer total render times than if you had optimized your settings manually. How to Fix the Warning