Hello everyone. Maybe this will be off topic but UE4 lags little to me when I add light to the scene. These are my specs:
Intel core i5 4440 @ 3.1 GHz 4cores
8GB DDR3 RAM
1TB HDD
AMD Radeon HD 6570 2GB DDR3
UE4 specs require at least HD 6870. Do I have now problem with my graphic card or it’s something else? 
Greetings!