Hello folks. I have Dell XPS 15z l511z and I wanted to upgrade my CPU i5 2410m but soon I discovered that I couldnt do that because my CPU is BGA. Then I saw on Ebay motherboard from same laptop but with i7 2640m. So I was wondering if I could replace my old motherboard with the motherboard with better CPU and does that laptop have 16x PCI e slot because I want external gpu. Thanks a lot