NVAPI fails to provide GPU information on K20c

I’m trying to use NVAPI to get GPU information on Windows Server 2012.
But NvAPI fails to return the data on K20c with NVIDIA_DEVICE_NOT_FOUND.

There are 4 K20c devices, but probably the display is driven by Microsoft Onboard chip.
If see the driver file for K20c cards under Device Manager -> Driver File Details, napi64.dll is present & source is Nvidia Corporation

Is NvApi supported on K20 cards?

Please guide