I have a 2010 mac pro. May of 2012 I ordered from OWC a 240 GB OWC Mercury Accelsior PCI Express SSD. The SSD lasted about a year. There would be times on boot up from my alternate backup that the card needed to be initalized, and was recognized as a 33 KB card. I reboot a couple of times in safe mode, then rest the NVRAM, and all would be fine. This failure to be recognized happened about four times until the SSD card totally failed May 2013. Went through the RMA process, replaced SSD, totally failed a week ago. Contacted OWC again, got RMA, sent card back, received new card today, except only 119 GB is recognized versus the 240 GB. Back on phone, OWC overnighting new card, all kinds of apologizes, said they will bench test before sending new unit. I blasted them, saying they were suppose to bench test the one I got. I have never been so disappointed in a product or OWC as I am now. I'm waiting for a supervisor to call so I can express my displeasure with the company.