MBP Unusably Slow After SSD Install

Oct 13, 2014
Reaction score
Hello everyone this is my first post in the forum because I am in a jam with my mid 2012 macbook pro unibody (model 9,2). I had purchased the machine from an old co-worker about a year ago, when I received he (a pretty savy mac guy) had removed the optical drive, and placed the 500 gb in that location. He had also upgraded the boot drive to a 256gb SSD. Recently I got the dreaded question mark upon boot, so after some research I ordered a new SSD from OWC. Below is the chain of events which has occurred.
• Installed the new SSD
• Did a fresh format on both the HDD and SSD
• Updated the firmware on both the mac and the new SSD
• Did an internet recovery of Lion onto the SSD which took about 11 hours.

Currently the SSD is running so slow the machine is unusable, I’m talking about 2 minutes to perform each mouse click on the OS. I have somewhat run out of options on what to do here everything seemed fresh but obviously isn’t working. It is worth noting I am able to install the OS on the HDD without issue, so it’s seemingly only the connection to the SSD. I am now on my second SSD from OWC, while trying to rule things out I returned the drive for a new one, still no luck. Any help!? Thanks!


Well-known member
Staff member
Jan 23, 2008
Reaction score
Keller, Texas
Your Mac's Specs
2017 27" iMac, 10.5" iPad Pro, iPhone 8, iPhone 11, iPhone 12 Mini, Numerous iPods, Monterey
What happens when you move the spinning hard drive (500 GB) back to its normal position and leave the SSD out of the machine? Does the machine return to normal operation as far as speed is concerned. I realize the 500 GB HDD is not going to be as fast as an SSD but you need to find out if the primary position including the SATA cable are OK.

Also, you need to make sure the SSD you purchased from OWC is compatible with your machine. Since the previous one that the original owner had installed was OK until it failed, it would seem there's a problem with the SSDs you're getting from OWC. You can speak with an OWC tech anytime on their 800 line. Have you done that?

Shop Amazon

Shop for your Apple, Mac, iPhone and other computer products on Amazon.
We are a participant in the Amazon Services LLC Associates Program, an affiliate program designed to provide a means for us to earn fees by linking to Amazon and affiliated sites.