I have a good Laptop and it isn't the best but I can use hundreds of mods with little issues and perfomance wise it doesn't much decrease any fps. For the lighting and shadows I use the Enchanced Lights and FX which doesn't make my game's performance suck in anyway. http://www.nexusmods.com/skyrim/mods/27043/? Playing with this mod is awesome and immersive since it makes certain places darker and forces you to really use light spells and torches. Second mod I use for immersion is Climates of Tamriel which adds so many cool stuff in skyrim. http://www.nexusmods.com/skyrim/mods/17802/? Sometimes I watch the Auroras in the game for fun They are compatible with each other and I have no problems with both of them. I have zero knowledge in Enbs so I use these two since it is simple and I am currently having fun with it.