Hello, I have a 2009 Mac Pro with a 640GB HDD (OS's), 1TB HDD, and a 240GB HDD (pictures and music). I have Mac OS X Yosemite, and almost an even partition split for a Windows 7 OS running on the 640GB HDD. I've recently been considering upgrading my boot drive to an SSD because I cannot stand the slowness of a hard drive anymore. My plan is to purchase a Samsung 850 EVO 500GB (maybe 250GB, I'm not sure yet) SSD and use my 1TB HDD to house files I don't necessarily need on the SSD. I would like to partition the SSD into a 250/250 (or a 125/125 if I go with a 250GB SSD) partition, one for Yosemite, and the other for Windows 7. I would like to house all my games, excess documents, and not-so-needed applications on the 1TB HDD, while keeping important, everyday use programs, on the SSD. Likewise for my OS X partition, however I wouldn't be storing any games (Xcode files primarily). Where I'm stuck at is how would I go about setting up the operating systems while having everything save to the 1TB HDD. I don't think it would be as simple as just changing the save directory for each download, because in windows applications save to 'Program Files (x86)' and that is setup when the OS is installed. Same would go for OS X I assume as downloads save where the OS is installed (i.e. 'Library'). Can someone help point me in the right direction to setting this up properly? Also, if someone has a different suggestion on what type of SSD to buy, by all means please let me know. Right now I am open to suggestions because I haven't purchased anything yet. Thank you for any help.