Because the Intel Core i3 2100 multiplier is locked, and without any Turbo Boost, the only thing that can be overclocked is the graphics core.
This is done by adjusting the graphics multiplier in the BIOS. The way the speed is worked out is by multiplying the host clock by 0.5 and then by the multiplier.
The highest we could get our sample to run stably was at 1.3GHz
CPU video encoding performance
1080p CPU gaming performance
1080p CPU gaming performance (maximum overclock)