'' This utility allows administrators to query GPU device state and with the appropriate privileges, permits administrators to modify GPU device state. It is targeted at the Tesla
TM, GRID
TM, Quadro
TM and Titan X product, though limited support is also available on other NVIDIA GPUs ''
maybe its just part of that ''limited supported cards'' and just don't function correctly or report it properly on you model card ?
https://developer.nvidia.com/nvidia-system-management-interface ''
Clocks Throttle Reasons
Retrieves information about factors that are reducing the frequency of
clocks. Only on supported Tesla devices from Kepler family.''
http://developer.download.nvidia.com/compute/DCGM/docs/nvidia-smi-367.38.pdf to me that's kinda how it maybe looking / your card may not be fully supported under that utility