What means "GPU rays per pixel value"?

V-Ray V-Ray for Rhino General
1

The note at the process window sounds like I could speed up the rendering, but I don’t know how. Can I do something?

(GPU mode; bucket mode 1/100, noise 0.015)

Maximum memory usage for texman: 0.00 MB
Can’t modify renderer while asynchronously preparing to start rendering.

Progressive RPP will be set to “true”

Progressive RPP must be disabled when Adaptive Lights are used. Disabling progressive RPP

GPU rays per pixel value of 1 is too low for production rendering. Rendering might take longer than usual. Recommended value is 16 or higher

Can’t modify renderer while asynchronously preparing to start rendering.

Preparing renderer…

2

During Interactive GPU rendering having SettingRTEngine’s gpu_samples_per_pixel parameter set to 1 ensures smoother updates.
When using the GPU engine with Bucket sampler, however, the gpu_samples_per_pixel value is not read. Instead, SettingsImageSampler’s dmc_minSubdivs and dmc_maxSubdivs parameters are taken into account. Therefore, the warning can be safely ignored.
Nevertheless, we will adjust the value to ensure the warning no longer appears in the progress log.

Regarding the string of warnings " Can’t modify renderer while asynchronously preparing to start rendering.", they occur when switching from Interactive to Production mode. This can be safely ignored as well.

Kind regards,
Peter