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EFI Update 2.9 Resolves 6Gb/s Drive Performance Issues in 13-inch 2012 MacBook Pro

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.

click to enlarge

After the update, though, not only did the test complete, but the results show the drive performing perfectly.

click to enlarge

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!

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  • Hello

    I have searched all over the net and this is the sole thread that describes my problem. I would appreciate very much any answer.
    My installed secondary drive SSD SATA 3 on the optical drive, can’t be formatted
    Error : partition failed wiping volume data to prevent future accidental probe

    My computer :
    MacBook Pro (13-inch, Mid 2012) (9.2)
    OS : 10.15.7 (19H1519)
    2.5 GHz Dual-Core Intel Core i5
    Main Drive : SATA 3 SSD

    On SATA Connectors I do see both SATA connectors are 6G compatible
    Intel 7 Series Chipset:
    Vendor: Intel
    Product: 7 Series Chipset
    Link Speed: 6 Gigabit
    Negotiated Link Speed: 6 Gigabit
    Physical Interconnect: SATA
    Description: AHCI Version 1.30 Supported

    Intel 7 Series Chipset:
    Vendor: Intel
    Product: 7 Series Chipset
    Link Speed: 6 Gigabit
    Negotiated Link Speed: 6 Gigabit
    Physical Interconnect: SATA
    Description: AHCI Version 1.30 Supported

    I bought a generic optical drive caddy (SATA 3 compatible) and a Kingston A400 SATA 3 SSD

    My question is:
    – Can I use SATA 3 SSD on the optical drive ?
    – If so, the choice I made for components is resulting in this failure, should I use the products in this page, the problem would be gone ?
    – I’ve read that replacing just the cable can fix the problem, would this be the case on my setup ?

    Note. This update, that supposedly should fix my issues (and dates back 9 years) can’t be installed on my system (This software is not supported on your system.) My EFI and SMC are up to date as of eficheck

    EFI Version: MBP91.88Z.F000.B00.2109131658 (Boot ROM Version: 424.
    Primary allowlist version match found. No changes detected in primary hashes.
    SEC Version: MBP91.AAPLEFI4.88Z.0014.I00.1302061204
    SEC allowlist version match found. No changes detected in SEC hashes.

    Thank you very much in advance.

  • An update for anyone worrying about this in 2020 (like me): I’ve installed two Samsung 860 EVO SSDs in my 13-inch 2012 MacBook Pro (model 9,2). One is in the main bay, and the other one is where the optical drive used to be, in an OWC Data Doubler.

    Based on what I’m seeing, looks like the SATA speed downgrade issue is completely gone.

    I just ran a test using Blackmagic. For the second SSD in the optical bay, the write speed is 489.3 MB/s, and the read speed is 513.5 MB/s.

    • Thanks! Stumbled on this site and read your current comment….quick ? though….are your drives both the same capacity? I already have a crucial 2TB ssd in my main drive, I just want to know if i should buy the exact same drive to swap out my optical…any thoughts? Cheers and thanks for the comment.

      • Hi, James!

        Yes, both my SSDs are at 1 TB each. Though I don’t think they need to be of the same capacity. I know some people have used a mix of SSDs and HDDs of differing capacities without issue.

    • Hi! Did you updated the firmware or just installed ssd? I have the same MBP and want to put a secondary ssd so want to know. Thanks in advance.

      • Hey there! Nope, I didn’t update the firmware—I just installed both drives straight away. Though I did download Samsung’s firmware updater tool for Mac, and it said that both SSDs were already running the latest firmware.

  • I have the Macbook Pro 13-inch mid 2012 (Non-Retina) which was manufactured in February-2015. I use only one OS which is the Windows 10 Pro. I already have a SSD in place of the main hdd and now I was thinking to remove the optical bay and put a Samsung 860 Evo (500 GB) in it’s place. Now, is the EFI Update 2.9 mandatory for me as mine was manufactured in 2015 and if yes can I get a Windows version of it? or if nothing, is there any other option by which I can use my 2nd SSD to it’s full potential speed?

  • This week I did all this. Fresh SSD in optical bay, as well as 16G new ram. My link speed is 6g, my negotiated is 3g. My computer is hanging randomly 1-3 sec after issuing commands, and can’t process working on multiple audio tracks anymore.

    MPB 13″ Mid 2012, running a fresh install of el captain, and the EFI 2.9 update looks like the miracle cure….

    “The software is not supported on your system”

    This is me:

    Boot ROM Version: MBP91.00D3.B0D
    SMC Version (system): 2.2f38


  • I have bought a second hand 13 inch mid 2012. It has an 250 SSD in the main bay and a 1TB HGST sata III in the optical bay. Although I have read that the optical bay of this model works properly with 6gs Im having troubles with it. When I try to transfer a big file after a while it unmount the HDD and give me an error.
    I think I have the last EFI version so I can’t upload it. find below information of my computer
    Nombre del modelo: MacBook Pro
    Identificador del modelo: MacBookPro9,2
    Nombre del procesador: Intel Core i5
    Velocidad del procesador: 2,5 GHz
    Cantidad de procesadores: 1
    Cantidad total de núcleos: 2
    Caché de nivel 2 (por núcleo): 256 KB
    Caché de nivel 3: 3 MB
    Memoria: 4 GB
    Versión de la ROM de arranque: MBP91.00D3.B0C
    Versión SMC (sistema): 2.2f44

    Please any help??


    • Hello Manuel,

      We are very sorry to hear of your experience. Please know we will be reaching out to you to further assist!

  • hi, I have a MacBook Pro mid 2012 13 inch. I replaced the optical drive with a data doubler and a 6gb/s hhd.

    however, I’m now using Yosemite, the Apple efi upgrade does not work…

    and the hdd will eject itself when there’s large file being transferred… please help

  • About to buy a 13″ 2.9Ghz dual-core i7 2012 Macbook Pro brand new. It has the standard 750GB 5400rpm HDD. I am also going to get the 480GB Mercury Extreme 6G with data doubler.

    I read on this blog ( that although the problems were fixed for the 2011 models, users were still experiencing issues with either a HDD or an SSD in the Optical Bay in the comment section. So I was wondering if it is worth me installing something in the optical bay at all? Given that although the issues were apparently solved, users still had issues.

    Moreover, if I do go ahead with the purchase, should i install the OWC SSD in the opti bay as the data doubler was designed with these drives in mind, or would the Mac HDD be best suited to the opti bay and does the data doubler support this drive?

    Finally, lets say I have put the Mercury Extreme SSD in the opti drive, would I install this firmware update for 2012 MPB on the HDD and then use disk utility to clone the HDD to the SSD (so the mac boots from it)? (after formatting the SSD of course).

    • There has been some confusion as to whether SATA Revision 3.0 speeds work in certain models and bays of the MacBook Pro so, to start, I’ll answer this specifically regarding the machine you’re looking to purchase:

      The 13-inch 2012 MacBook Pro never had any issues running a 6Gb/s capable HDD / SSD in the main hard drive bay – so all is good there.
      Now, once you’ve upgraded your 2012 13-inch MacBook Pro with EFI Firmware update 2.9 (which updates the computer itself, not a specific drive), the optical drive bay with Data Doubler will be able to utilize a 6Gb/s capable HDD / SSD as well.

      I would personally suggest if you are going with a one hard drive, one solid state drive setup that the SSD be installed in the optical bay, and setup as the boot drive for the machine. The only benefit this offers is that the main hard drive bay does employ some SMS (sudden motion sensor) protection for a platter-based drive against accidental drops that doesn’t exist in the optical bay.

      Now, that said (and speaking of a different model year of MacBook Pro now), the other blog post you’re referring to is for the 2011 models where 6Gb/s performance was resolved for the main hard drive bay – the optical bay is a different story and depends on both the original link speed and which model (13-, 15-, or 17-inch) of 2011 MacBook Pro you have as to whether the optical bay will be able to utilize a 6Gb/s capable drive as well.
      But in short, for the 2011 models:
      13-inch – 100% no issues with 6Gb/s HDD/SSD in any bay that has 6Gbp/s available link speed.
      15-inch – 100% no issues with 6Gb/s HDD/SSD in main bay after EFI update, no-go with 6Gb/s HDD/SSD in optical bay.
      17-inch – 100% no issues with 6Gb/s HDD/SSD in main bay after EFI update, no-go with 6Gb/s HDD/SSD in optical bay.

  • I just bought a brand new Macbook Pro 2.6 Ghz quad i7 8 RAM in combination with the OWC 480 GB Extreme pro data doubler kit. Ive done some research and read on several blogs that there has been a problem with installing the SSD drive in the optical bay in regards to the hibernation function.

    I want to install my SSD in the optical bay but would reconsider this if this hibernation problem has not been fixed yet. Can anyone tell me the status of this known problem?

    With my setup, would it be recommended to instal the OS and all applications on the SSD in the optical bay?

    Thanks for your help!

    • On 3/18/11, SandForce released firmware update MP4 that fixed known hibernation issues and the 2012 MacBook Pro 15” optical bays will support an OWC 6G SSD without any issues – so you can upgrade with confidence.

  • Hello, sorry if this is redundant, but I’d like to know that I’m on the right track here.

    I’m looking at :
    Refurbished MacBook Pro 2.7GHz Quad-core Intel i7
    Eligible for OS X Mountain Lion Up-to-Date Program

    Originally released June 2012
    15.4-inch (diagonal) LED-backlit Hi-Res antiglare widescreen display, 1680-by-1050 resolution
    8GB (2 x 4GB) of 1600MHz DDR3 SDRAM
    1TB Serial ATA @ 5400 rpm
    8x double-layer SuperDrive (DVD±R DL/DVD±RW/CD-RW)
    NVIDIA GeForce GT 650M with 1GB of GDDR5 memory

    This will be used for Final Cut Pro x, Motion and After Effects. What I’d like to do is replace the HDD, with a 256 SSD boot drive, and replace the Optical drive with Data Doubler, with a 512ssd being used as a WORK DRIVE when I’m on the road. Otherwise I use thunderbolt or FW800 drives for basic cuts.

    Do I understand correctly that the 6gb SSD connection WILL work in this model of MBP? And if so, can someone suggest the best drives to order… I’m only familiar with the SSD I’ve got in my Hackintosh studio edit rig.

    Anyone editing multicam on their MBP in this type of configuration>?Love to hear how your experience has been if you have.

    Thanks for any help!


  • If I just bought a mid 2012 MBP off ebay, and the seller installed a formatted SSD in the HDD bay, should I install Mountain Lion on it first and THEN move it to the optical bay (and install a 750GB HDD in the original HDD bay) or move the SSD to the optical bay first, then install Mountain lion on it? Or should i just leave the SSD in the HDD bay and install the new HDD in the optical bay?

    thank you in advance!

    • Each is really just a matter of personal preference. Any of the suggested methods would work.

  • Can anyone confirm this?

    I just ordered a 120 Mercury Electra 6G SSD off of OWC and a new mid-2012 13″ Macbook Pro. And I’m now wondering where to install the SSD, as I heard it would be less noisy to put it in the optical bay. (And I thus would be leaving the 500gb HDD where it is)

    Reading this thread, it’s seems unclear whether that will work or not… (And made me thing I should have ordered a 3G SSD instead…)

    Thx for letting me know!


    • You have a 13-inch 2012 MacBook Pro and you want to get the performance benefits of having an OWC 6G SSD (the 120 Mercury Electra 6G SSD in particular) in the optical bay via a Data Doubler while leaving the original drive in the hard drive bay.

      As long as your EFI firmware is up to date, then that will work.

      • All right,

        Thx for the quick reply! And I guess I would be able to boot from the SSD in the optical bay without a problem, with this new firmware?

        • Correct, it’s just a matter of choosing which drive is your boot drive under System Preferences > Startup Disk.

  • Just installed a 6G SSD in the optical drive of a 15″ macbook pro and things appear to be working just fine.

    Just to be certain, is there anything I can do to confirm that I’m getting full speeds and not limited by the boot drive being in the old optical drive? It appears you guys are using a program called disk tester?

  • 2012, 13″ Macbook Pro.
    SATA3 480 gig SSD (sandisk) x2
    Data Doubler Optical Bay Enclosure

    Drive in the standard hard drive spot works fine.
    Drive in the Optical bay will not even formart.

    Solutions that DO NOT work
    (again, these DO NOT WORK):
    – EFI 2.9 Update
    – 2012 Macbook Pro 13″ SATA Cable
    – 2011 Macbook Pro 13″ SATA Cable (I swapped because the 2011 13″ was supposed to work).

    I’m at a loss here.

    • You’re 13″ model may have other deficiencies that the current EFI was not able to overcome. Apple doesn’t officially support any drive in the optical bay. Have you tested the standard hard drive in the optical bay to see if that operates ok? Of other note, our SSD testing is with our OWC Mercury drives which can also make a difference.

      • As an update:

        – Yes, the standard SATA2 drives work fine in the optical bay. Tested a few.
        – The drive is SEEN by the OS, so I formatted it by putting it in the main bay, and launched to the recovery partition in my OS loaded driv in the optical bay. The 200mb partition launches just fine from the optical bay, however the Mac OS partition does NOT.
        – Once it was formatted, I swapped the drives back (damn I’m getting good at this), and it was seen by the OS, the link speed was registered as 6 GB/s, but I could NOT copy any files to the drive EXCEPT a small .txt file.

        – So the drive SIZE might have something to do with it.
        – The drives write speed might also have something to do with it. (I’ve noticed that with most SSDs, they take a few moments to get up to actual max speeds).

        So, if the OWC drives do in fact work, maybe they’re just a slower max speed that doesn’t choke the system?

        Is there a way to possibly limit the optical bay link speed to 3gb/s? 3gb/s SSDs are few and far between (especially in the higher capacities), so that could be a better solution?

        I know it’s an OWC forum, but I AM using the datadoubler, which you say works with 2012 Macbooks, So, it should work with ANY SSD, not just yours. Or at least say that when purchasing it.

        • #1 – the OWC SSDs are not slower than the Sandisk – this is not a factor nor is the capacity of the drive…

          What is factor is the line signal strength and noise. What we have found is a difference with our drives is our metal enclosure. I believe the Sandisk has more of a synthetic casing and it is possible that this results in greater noise or other impact in the optical bay. hard drives are also encased in a metal shell.

          With the current EFI, we have found no issues with our OWC 6G SSDs and no issues with 6G 2.5″ hard Drives operating at 6Gb/s SATA 3.0 link in the 13″ MacBook Pro. Prior to the EFI update, 6Gb/s was not stable at all in the 13″ 2012 model. Also, before and after the update there had been no issue with 6Gb/s SATA 3.0 in the optical bay of the 15″ 2012 MacBook Pro.

          So – I’d surmise that either the Sandisk SSD has a physical difference which prevents success in the 13″ optical bay or the MacBook Pro 13″ you have still remains with issue even after the EFI update.

          Apple of course makes no statement or guarantee of 6Gb/s capability in the optical bay despite providing the SATA 3.0 6Gb/s link capability there.

          • What capacity SSD did you test?

            And if in fact it IS something wrong with my Mac (and my girlfriend’s 2011 as well), then the claim that the datadoubler is tested and works in 2012 macbooks … should probably be “it only works with an SSD in OUR 2012 macbook., and only with OUR SSD”

      • Just for those people searching for solutions, here’s my setup:

        Model Name: MacBook Pro
        Model Identifier: MacBookPro9,2
        Processor Name: Intel Core i7
        Processor Speed: 2.9 GHz
        Memory: 16 GB
        Boot ROM Version: MBP91.00D3.B08
        SMC Version (system): 2.2f38

        – OWC Data Doubler
        – Sandisk Extreme Pro 480 gb SSD in standard bay
        – Sandisk Extreme Pro 480 gb SSD in optical bay ——– seen by system, link speed 6 gb/s, will not write files after formatting in the standard bay

  • In reference to this and the original “” Expand the 2012 MacBook Pros with an OWC Data Doubler.”” Blog,
    A couple questions: (For 2012 non retina 15″ macbook pro)
    #1 – I called apple sales dept. and asked if any of the SSD’s to order from Apple with the (new 2012 mbp 15″ non retina version) were 6g drives? They couldnt answer my question and said they didn’t know. Ultimately I want two 6g SSD’s in a new 2012 non retina 15″ mbp Im about to purchase. So are any of the Apple options that come with the mbp purchase 6g SSD’s or are they all 3g drives that come from Apple?

    #2 – And if I go with two of your OWC 6g SSD’s, does it matter what drive I order with the new MBP from Apple ? I’d like to order the cheapest HDD (750GB Serial ATA Drive @ 5400 rpm). Would there be any issues ordering this drive if planning to swap it out for OWC mercury extreme 6g SSD or do I need to buy the cheapest SSD for some reason if planning to swap out with OWC SSD ? Wondering if the “Sudden Motion Sensor” feature with HDD would cause any problem when switching to OWC SSD.

    #3 – Lastly, out of all your OWC drives Is the mercury extreme pro 6g still the fastest performance and best option for 2012 MBP 15″ non retina version ? (I want to put one in the main bay and a 2nd one in the optical bay)

    Im seeing this mercury enterprise pro 6g SSD but wasnt sure if its a better option for my needs being heavy video editing and dual recording of uncompressed HD video with simultaeneous effects and going into the MBP

    • #1 – Apple uses what Apple has in their supply queue. I believe they can not answer because what they use is not consistent, more than one type will be used based on availability, etc at build point.

      #2 – No, the factory drive has no bearing on cabling, or other hardware that would affect a drive you’d replace said factory drive with.

      #3 -The Extreme Pro 6G is the highest performance option for the Mac today and is correct for MacBook Pro 2012 (non-Retina). The Enterprise Pro is really not ideal for laptop use due to it’s higher power requirement. Further, somewhat overkill… The Enterprise Pro has features required for data centers / mission critical database server functions with data hardening in the even of unexpected power loss/critical server failure during transactional data recording. Not the kind of stuff happening with normal desktop/laptop use unless used as a high level database server.

  • The update didn’t fix the issue for me. I still can’t use my Samsung 830 in the Optical Bay….

    It just doesn’t let me boot from it.

    • EFI update didn’t help me with a Samsung 830 and a cheap caddy in the optibay (though, the stock HDD boots and works fine in the optibay, and the 830 SSD boots and works fine in the primary HDD location). Is it only the Mercury SSDs that are working there, the OWC data doubler caddy, or are both necessary to get the SSD functional in the optibay?

  • “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.”

    This is misleading. AFAIK, the 2011 15″ and 17″ MBPs still cannot reliably use a 6G SSD in the optical bay. The firmware update you link to allowed for reliable use of 6G SSDs in the main hard drive bay, but had no effect on the optical bay (a point you make in the link).

    You gave me a bit of false hope there that the 2011 optical bay issue had been resolved…

    • Eventually, though, an Apple firmware update resolved the problems in the 15-inch and 17-inch models in the main drive bay.”


  • Neither the Ubuntu nor the Bootcamp Extreme Pro 6G SSD firmware updaters work on my mid-2011 iMac (12,2). The Ubuntu system doesn’t load, while the Bootcamp updater will launch, seems to go through the update process, but leaves the SSD drives unchanged. I have two 120GB drives that I run in RAID0 — I’ve tried deleting the RAID, but still no luck. Any idea when a new version of your firmware updater will be released to address this?


  • What about 13″ MacBook5,1 (Late 2008)? I had originally planned to stick an SSD in my MacBook, then read about problems with the diskdoubler optical bay use, and instead installed the SSD in my MacPro. I would love to add an SSD to my MacBooks Optical bay. Are all MacBook model issues fixed now?

    • EFI Update 2.9 was released for the 2012 MacBook Pro – the firmware update is for those machines only.