I don't have 16GB of RAM, I only have 8GB. Should I spend money, even if it won't affect gaming, or should I just let it be? And also, I don't know if I have one memory part (1x(GB) or a two piece set (2x4GB). If I have a 2x4GB, can I leave one of the stock parts or it just wn't be compatible? And storage isn't a problem either, I have a 750GB HDD (for the OS and other computer files) and a 120GB SSD (for games), could it be the graphics card failing me?Thank you for the help!