Hi Guys, I am considering adding a SSD to my new XPS 15. I searched up some previous posts and it seems that out XPS 15(L502X) does support SATA III. I am wondering do both the primary HDD SATA port and the Optical SATA port support SATA 3 or only the primary port? If I were to install a SSD, which position should I put it , the primary HDD position or the optical positiion? Why ? Thanks!