GPU frequency management is one important innovation in the Kepler architecture. GPUs normally use a clock rate which is fixed at a certain level which is supposed to be safe under any usage scenarios. This clock rate is usually selected with a large safety margin, so that the graphics card worked within permissible power consumption limits even at the highest load. But it means that in ordinary applications the graphics card has a large reserve in terms of power consumption and heat dissipation.
Nvidia suggests that this reserve can be converted into increasing GPU clock rate and, consequently, performance in such applications. So, the Kepler has a special subunit that monitors key GPU parameters such as clock rate, power consumption, temperature and computing load, and controls the graphics card's frequencies and voltages basing on that data. The technology is called GPU Boost.
For example, the base clock rate of the GeForce GTX 680 is 1006 MHz. The card is guaranteed to have it whatever 3D load. However, in most 3D applications it will be automatically increased to 1058-1100 MHz, i.e. by 5-10%. And in some cases the frequency will be increased even higher. So, this technology is an efficient way of getting all the performance the graphics card can give without going out of the permissible power consumption limits.