Stefan Mileschin

With the new 4th generation Intel Core processors, code-named "Haswell", Intel introduces new technologies for reducing the power consumption of the CPU during sleep. The new deepest sleep state, called C7, will be able to reduce the power consumption of the CPU to only 0.05A (0.6W). As this occurs in the deep sleep state, when most other 12V devices are either in low-power states or turned off, this can reduce the 12V load on the power supply significantly. For some power supplies this low load can cause voltage regulation issues, if combined with high loads on the minor rails (3.3V and 5V).

http://www.techpowerup.com/184239/fr...h-haswell.html