Identifying a GPU's installed driver

// Access the cluster's resource manager:
RED::Object* resmgr = RED::Factory::CreateInstance( CID_REDResourceManager );
// Get it's graphic device interface:
RED::IGraphicDevice* idevice = resmgr->As< RED::IGraphicDevice >();

// Query the list of all GPUs on the system:
RED::Vector< RED::GPUID > gpulist;
RC_TEST( idevice->GetLocalGPUs( gpulist, false ) );

// Retrieve the installed driver for the first GPU:
RED::String drivername, driverdll;
bool newer, older;
RC_TEST( idevice->GetLocalGPUDriver( drivername, driverdll, newer, older, gpulist[0]) );

The RED::IGraphicDevice::GetLocalGPUDriver looks for the driver installed for the specified GPU. Note that the GPU must be present on the local computer (therefore, it should have been retrieved by a RED::IGraphicDevice::GetLocalGPUs).