intel hd4000 gpu core frequency locked at 350 mhz.

In my lenovo u510 Intel hd4000 gpu core clock frequency is locked at 350 mhz.even on playing game like cod:modern warfare 2 it stays at 350 mhz.it never rise up. constantly remain at 350 mhz.

I have tried different versions of intel hd4000 driver and power modes(balanced,high performance).but gpu core clock stay at lowest frequency all the time.i checked the gpu core freq.  using gpu-z and intel XTU.