The i7-4510u is a little more powerful than the newer i5-5200u in terms of processing power because of the higher clockspeed (3.1GHz vs 2.7GHz). However, the i5-5200u can process more is bit more instructions per 1Hz then the i7-4510u so the performance difference is actually a little less than the 400MHz difference in clockspeed. The i7 also has 1MB more internal cache which can help a bit in CPU intensive tasks.
When it comes to integrated graphics performance, the newer Intel HD 5500 is on average around 15% - 20% more powerful than the older Intel 4400; performance varies depending on the game.
Really depends on what you're going for. Broadwell (the i5) is slightly more efficient, and hyper threading (the i7) is useful for tasks that utilize many cores/thread (not gaming). For gaming, pick the cheapest one. For multitasking, the i7 wins. Also CPU boss is not a very accurate test.
The i7-4510u is a little more powerful than the newer i5-5200u in terms of processing power because of the higher clockspeed (3.1GHz vs 2.7GHz). However, the i5-5200u can process more is bit more instructions per 1Hz then the i7-4510u so the performance difference is actually a little less than the 400MHz difference in clockspeed. The i7 also has 1MB more internal cache which can help a bit in CPU intensive tasks.
When it comes to integrated graphics performance, the newer Intel HD 5500 is on average around 15% - 20% more powerful than the older Intel 4400; performance varies depending on the game.