Warning Num Samples Per Thread Reduced To 32768 Rendering Might Be Slower Jun 2026

This warning indicates that V-Ray is experiencing VRAM (Video RAM) limitations and has automatically lowered a specific setting to avoid a total crash. While it saves your render from failing, it often comes at the cost of significantly increased render times.

Let's write. is a comprehensive, long-form article optimized for the keyword . It addresses the root causes, technical implications, and practical solutions for users encountering this message.

Remember: reliable rendering at 95% speed beats a crash at 100% speed every time. Keep creating, and don’t let a console warning slow you down—unless it’s the render itself 😉 This warning indicates that V-Ray is experiencing VRAM

This is the #1 culprit. When rendering with GPU (CUDA/Optix), each thread needs a certain amount of VRAM to store sample data, ray states, and temporary buffers. If your scene is heavy—high-poly geometry, 4K/8K textures, complex shaders, volumetrics—the GPU might not have enough free memory to handle the desired samples per thread. The driver then forces a reduction.

The software limits how many data samples (e.g., pixels, rays, sound samples) each CPU/GPU thread can handle at once. The limit was lowered to 32,768 — probably because of hardware constraints (e.g., low memory per core, or driver-enforced safety). is a comprehensive, long-form article optimized for the

: Close other GPU-heavy software like Substance Painter, Photoshop, or Chrome to free up memory for your renderer. SketchUp Community

Downscale textures that don’t need high resolution (e.g., B. Adjust Render Settings Keep creating, and don’t let a console warning

Silence.

Set an optimal tile size (e.g., 256x256 or 512x512 for modern GPUs).

Set a target noise threshold (e.g., 0.01 for high quality, 0.005 for production).

❌ On some hardware/drivers, it could be 16384 or 65536. The exact number varies.