Whenever a computer is idle, we can either put it in standby (where DRAM is still active) or we can let it hibernate. Assume that, to hibernate, we have to copy just the contents of DRAM to a nonvolatile medium such as Flash. If reading and writing a cache line of the size 64 bytes to Flash requires 2.56 J and DRAM requires 0.5 nJ, and if idle power consumption for DRAM is 1.6 W (for 8 GB), how long should a system be idle to benefit from hibernating? Assume a main memory of size 8 GB.