Warning Num Samples Per Thread Reduced To 32768 Rendering Might Be Slower ((top)) Link

Warning: Num Samples Per Thread Reduced to 32768 - Rendering Might Be Slower

Why does this happen?

• Driver or API limits (e.g., OpenCL, CUDA, Vulkan)
• Low GPU VRAM or limited thread-local memory
• Software fallback mode (e.g., when optimal settings fail)
• Large render settings trying to exceed per-thread buffer capacity

“Override it,” he repeated, softer. “I need to see her clearly.” Warning: Num Samples Per Thread Reduced to 32768

: Rendering at 4K or higher significantly increases the memory buffer requirements. Background Apps Driver or API limits (e

Performance Hit: Because the scene’s complexity (geometry, textures, frame buffers) is too large for your available VRAM, the renderer must "chunk" the work differently, which typically leads to a significant loss in rendering speed. “Override it,” he repeated, softer

This article will dissect every aspect of that warning: what it means, why it appears, how it affects performance, and—most importantly—how to fix or work around it.

: Other open programs (like Chrome, Substance Painter, or Photoshop) are "stealing" VRAM that the renderer needs. Complex Features