How is the difference performance-wise between the i7-6xxm (dual core) and the i7 7xx (quad core)? is the performance difference large? and would the battery life be significantly better with the i7 dual core? i heard that when some of the cores arent needed they power off so even the quad core should not use too much power if its like idling or just surfing the web am i correct?
so mainly what i want to know between the i7 dual and quad core is performance and battery difference. thanks