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

Understanding the "Warning: num samples per thread reduced to 32768" Error

If you are using NVIDIA, switch from to NVIDIA Studio Drivers . Studio drivers are optimized for long-running kernels (rendering) and are less likely to trigger aggressive TDR limits that lead to sample reduction. 4. Check Your "Max Samples" Setting Understanding the "Warning: num samples per thread reduced

Warning: num samples per thread reduced to 32768 rendering might be slower Understanding the "Warning: num samples per thread reduced

Older NVIDIA drivers have lower thresholds for thread allocation. Understanding the "Warning: num samples per thread reduced

The second half of the warning is the most frustrating: "rendering might be slower."