the VK_LAYER_NV_optimus layer looks at the __VK_LAYER_NV_optimus environment variable. The value NVIDIA_only causes VK_LAYER_NV_optimus to only report NVIDIA GPUs to the Vulkan application
the VK_LAYER_NV_optimus layer looks at the __VK_LAYER_NV_optimus environment variable. The value NVIDIA_only causes VK_LAYER_NV_optimus to only report NVIDIA GPUs to the Vulkan application