Generally i have seen NVIDIA and ATI providing the graphics clock frequency in specifications of their products. How do i come to know the same of Intel HD graphics?
Intel HD Graphics overtakes discrete 8400 GS
It depends on the processor type. Generally, i5 and i7 have faster clock speed capability due to their Turbo Boost technology. i3 obviously doesn't have that.
Here's the list:
See this link. http://en.wikipedia.org/wiki/Intel_GMA#HD_Graphics_.28GMA_HD.29