Hi, First let me confess to me being a mac newbie , I have a macbook pro, stats below. 13', Mid 2012 processor 2.5GHz Intel Core i5 Memory 16GB 1600 MHz DDR3, i was able to upgrade this myself OS X Yosemite Version 10.10. I have decided to upgrade my hardrive to a Crucial M55O 256gb SSD and move my Superdrive to the optical bay. I have read , made notes and saved links to perform the swap without any problems, I hope. I would like to use my SSD drive for the operating system and applications, and the superdrive for everything else. Here are my questions. Do I need to set my SSD drive to master and my Superdrive to slave, if yes how is this done?. I am aware how it is done on windows pc. I would like to be able to choose which drive I save information on rather then let the mac decide where it is stored.How could I do this please ? My thoughts it stops the mac slowling down by acessing both drives to retrieve an application that has files saved on both drives. What would be the most efficent method of setting up the drives? Fusion or indepent operation? Lastly, any chance of a link to any of my questions? I would truly be grateful for any help. Thank you, a very nervous but equally excited newbie. Johnrho.