Released June 2012, Model A1278. Intel processor with Turbo Boost, Up to 512 MB DDR5 Video RAM

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Second HDD in Optical Bay keeps shutting off

I read the question that @gautam2402 asked Second HDD in optical bay not working properly I am having almost the same exact problem except I am using a Samsung Seagate 2TB (ST2000LM003). My main HDD is a Seagate Momentus XT 750 GB and it has been working fine.

The drive drops after some use and file transfer. I am assuming this is because the drive is a SATA III while the SATA connector for the Optical drive is SATA III. If I reboot my computer the Secondary drive will show and I can transfer files for a few minutes before the drive stops working and the HDD disappears from the system.

Because of my location it is not easy for me to buy a new hard drive. Is there anyway to use the Samsung Seagate HDD I already own in the optical bay as a second HDD. I noticed something about upgrading the MacBook Pro EFI Firmware. But when I go to install I get an error.

Block Image

Any suggestions moving forward. Are there anyways to via firmware, software or 3rd party hardware to use a SATA III drive inside the optical drive.

Any help would be amazing.

Answered! View the answer I have this problem too

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I should point out you really have a Samsung drive here. Samsung sold their HD drive division to Seagate which does confuse things ;-}

The reason I point this out as the hardware designs of the drives them selves are very different between the two divisions.


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Personally I don't do dual drive setups on Unibody systems as there are just to many failures for different reasons. Often the issue is the optical drives SATA port which is not what it claims! The problem is the controller chip Apple used and Apple them selves not doing a very good job making sure the port was able to support a SATA III device. Here's a good writeup on the issue: OWC -Data Doubler. Note the comment in Red at the bottom. It makes no difference who's unit you use this is a failure within the logic of the logic board. The other is the lack of crash guard protection for the HD if it does not have it onboard as Apples system is part of the HD SATA port and not the optical drives SATA port. So if you move the system with the drive running you could damage the drive. Lastly, the drive does not spin down when you put the system in sleep mode. If this was a SSD then it's no big deal, but for HD's it could be.

In this case I think you have a defective drive. What happens when you remove the drive? Did you alter the OS in anyway?

As to the EFI update: Review this Apple T/N About EFI and SMC firmware updates for Intel-based Mac computers Just make sure your at the levels listed or newer. Use the links here for the needed update if you have something older.

Update (05/07/2016)

To find out if your HD has onboard crash guard you'll need to review the spec sheet of the drive. You may find some versions offer it, others not.

As far as the EFI update: Sorry to say Apple is not forthcoming on all of the alterations it has. The two areas I know of is HD & memory both have gotten a few updates. I would hold off on applying the update until you know your system is stable.

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Thanks for your answer. It was very helpful. However I am still a bit confused. The information on the OWC-Data Doubler page you linked referred to 2011 Macbooks and mine is a 2012. My System Hardware SATA description says that the optical bay supports 6 Gibabit. I was not aware of the Disk not shutting down during sleep. How do I check to see if my hard drive has onboard disk protection? Also what is fixed by the EFI Update? I looked and my EFI needed to be updated and so I downloaded the patch. Can I try to use the drive with this configuration? Thanks so much for your help with this.


The point of the link was just informative. I had found a few '12 models that didn't like the dual drive setup as well which was the point I stopped doing them.


Also I had already applied the EFI Update. Is this something I should undo? If so how do I go about doing this?


No, you should be fine.


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