Which CPU models are you trying to compare?
Generally speaking, the average processing performance increase from 4th to 5th gen is only about 4%. The Core i7 comes as either dual core ("u" and "m" models) or quad core ("hq", "mq" and "mx"). If you are comparing a dual core i7 to an i5, then the difference is basically the clock speed.
On the graphics side of things, the 5th gen Intel HD 5500 is roughly 15% - 20% more powerful than the 4th gen Intel HD 4400.