Przemion

I think this explain a lot, "OS X Yosemite and third-party SSDs: Here's what you need to know" - http://www.zdnet.com/os-x-yosemite-and-third-party-ssds-heres-what-you-need-to-know-7000035872/

I think is not SSD but enclosure, and I would bet my money on Thunderbolt, since U said on USB 3.0 it was working, od did I get something wrong ?

I upgraded 3 computers so far, all with SSD, two from OWC one from Samsung EVO, all works fine. IMHO I think it might be something else (like this external enclosure). All drives are in different Macbook's Pro.