When the 2012 MacBook Pros were released, we found that SATA 3.0 SSDs—such as the OWC Mercury EXTREME Pro 6G and the Mercury Electra 6G—exhibited poor performance and reliability in the 13-inch model when installed in the optical bay via an OWC Data Doubler, while the same SSDs in the 15-inch model worked just fine.
This was similar to what happened in 2011, where (ironically enough) the 13-inch models were the only ones able to handle our Mercury 6G SSDs in the optical bay at first. Eventually, though, an Apple firmware update resolved the problems in the 15-inch and 17-inch models in the main drive bay.
As it turns out, the same thing happened to the 2012 models. Yesterday’s EFI Update 2.9 for MacBook Pro appears to have fixed the problem.
We ran some benchmark tests with an OWC Mercury 6G SSD in the optical bay of a 13-inch 2012 MacBook Pro. Prior to the update, the drive would consistently drop its connection.
After the update, though, not only did the test complete, but the results show the drive performing perfectly.
So if you have a 13-inch 2012 MacBook Pro and you want to get the performance benefits of having an OWC 6G SSD in your optical bay via a Data Doubler, then head over to Software Update and run that EFI Updater!