I know this is a (quite) frequently asked subject but I considered that my question was not answered on previous threads (which I searched through the Forum search function) so I'm hoping you guys can help me out. Here's my set of questions: 1) When replacing my MBP13 (mid-2012) Superdrive in order to upgrade my Mac storage capacity, where should I put the SSD: in the Superdrive slot or in the original HDD bay? I'm asking this because I've read that the HDD bay supports better transfer speeds than the Superdrive bay. A quick check on "About my Mac" shows me that my Mac HDD bay supports 6 Gigabit of Link Speed and 3 Gigabit of Negotiated Speed Link, whereas the Superdrive bay speeds remain the same for the Link Speed but decrease to 1,5 Gigabit for the Negotiated Link Speed. 2) Once I've installed the SSD and upgraded my storage, which way would be the best in order to simplify managing two internal discs: creating a DIY Fusion Drive, simply moving my user folder to the HDD, or any other method…? This last questions is concerning how could I proceed to make my Mac think that both discs are just one, in order to not having to manage files/folders/etc. things manually. Thank you very much in advance. Hope I was clear enough when writing down my questions, if there's any additional information that I could provide to help you better understand my questions, please don't hesitate to ask.