Building fully functional instant on/off systems by making use of non-volatile RAM

In this paper we present our experience in building a fully functional computer system that can be turned on and off instantly to zero or minimal power state. This feature is not possible with current (embedded) computer systems such as cellular phones or smartphones that are based on full fledged operating systems, as booting such a system takes a long time. This inconvenience forces users to keep their devices on even when they are not needed causing power wastage, which has become an important social issue. In this paper, we show that system instant on/off can be attained by adopting new nonvolatile RAM, such as PCM or FeRAM, as part of main memory and modifying the operating system appropriately. Our experimental measurements show that our system, on average, turns on in 0.09 seconds and turns off in 1.21 seconds.