RT GPU Textures and Size?

[biochemical_animations]

In the render settings, why is the gpu texture size not greyed out when full-sized textures is selected for gpu textures.

For example, if I have a dome light with an 5K hdri loaded, how is the resolution controlled. By the Res setting in the dome light, or the textures setting in the render setup or the texture size...I'm confused which one sets the size and if a setting is overriding another setting. TIA

[Zdravko.Keremidchiev]

Please keep in mind that the CPU uses the original texture size for camera rays and different texture size (which you can control) for the DMC sampler. The GPU in another hand uses only one texture size for the DomeLight which can be controlled only with the VRayLight "Texture Res" value.
Furthermore the "GPU texture size" field doesn't get disabled when "Full-size texture" option is used because this value still controls the size of the procedural textures in the scene. If you use "Resize all textures" the texture size will affect both the procedural and the bitmaps.

The Dome light "Texture Res:" value sets the texture size which the DMC sampler will use to sample the image and determine its importance sampling. So it will only affect the blurry values. The Texture options in the Settings tab sets the size which can be used for tiled OpenEXR files. The "GPU texture size" will resize the image for the GPU engine.

[biochemical_animations]

Thanks Zdravko.