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

: High values (above 3000) consume a lot of memory. Keeping them between 1000 and 3000 is generally ideal for 4K renders. Check High-Memory Features : Disable or simplify Displacement Subdivision

Try disabling displacement in the Global Swatches settings to see if performance improves.

Understanding what chokes your VRAM is essential to preventing this warning: : High values (above 3000) consume a lot of memory

The num samples per thread reduced to 32768 warning is your GPU's way of saying, "I'm trying to do too much at once, so I'm slowing down to stay safe." By optimizing your and ensuring your drivers are up to date, you can usually clear this warning and regain your rendering speed.

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 😉 Understanding what chokes your VRAM is essential to

Use the Optimizing Memory Usage Guide from Chaos Support to reduce scene heavy-hitters.

Some versions of CUDA, OpenCL, or Metal have internal limits on how many rays can be in flight per thread. NVIDIA’s CUDA runtime, for example, might cap the workgroup size. When the render engine requests a higher value, the driver clamps it down and returns a warning. Some versions of CUDA, OpenCL, or Metal have

Number of samples per thread reduced to 32,768. Rendering might be slower due to hardware stability limits.

: Sometimes VRAM doesn't clear properly due to memory leaks. Restarting your 3D software or your PC can free up "stuck" memory.