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Firmware Update Enables 6Gb/s in 2011 iMacs.

Thursday, May 5th, 2011 | Author:

Well… that was quick! Just two days after they were released, the 2011 iMacs have a firmware update.

While iMac EFI Update 1.6 is described as including “fixes that improve performance and stability for Thunderbolt,” it would also seem that an unadvertised benefit is that it also unlocks the full 6Gb/s, SATA 3.0 capabilities of two of the internal drive bays.

Unfortunately, the optical bay remains at 3Gb/s.

We’ll be doing some testing and posting some numbers to show the speed differences, and posting them as soon as we get them, so hang tight.

Oh, and for what it’s worth, it appears there’s also an update for the 2011 MacBook Pros, which includes “fixes that resolve an issue with Turbo Mode in Boot Camp, and improve performance and stability for graphics and Thunderbolt.” No word on if it addresses any issues with 6Gb/s SATA in the main hard drive bays of the 17” model.

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    1. James says:

      Just as an FYI to any who are interested – I looked in system profiler and while my SATA chipset reads 6GB with firmware IM121.0047.B0A, the 2TB Hitachi hard drive that came with my 2011 iMac is only a 3GB model. Interesting…

      • Mario says:

        I know it’s nearly 2013, but I came across a problem with my imac 27 2011. As the prices of SSD fell a little I bought Samsung 830 256GB 6Gbit for my computer to only find out that it was working as 3Gbit. After looking for updates and firmwares, I had a closer look at System Profiler. In Serial-ATA section I had HDD with 6Gbit link (negotiated 3Gbit), DVD drive with 6Gbit link (negotiated1,5Gbit) and SSD with 3Gbit link (negotiated 3Gbit).
        Long story short – I’ve swapped SATA sockets with my DVD drive. It looks like when Apple built my computer, they’ve put it together incorrectly. Now my SSD works at full speed with SATA III. I hope this helps few people. I sure thing could’ve used this information.

      • Simon Harris says:


        The system profiler on my 2011 iMac shows the following under serial ATA:

        Vendor: Intel
        Product: 6 Series Chipset
        Link Speed: 6 Gigabit
        Negotiated Link Speed: 3 Gigabit
        Description: AHCI Version 1.30 Supported

        So my question is this ‘Negotiated Link Speed’ – it’s showing 3 Gigabit, is this not the maximum speed for only Sata 2 drives which top out at 375mbs (this is the exact speed I am topping out at) ? The SSD drive I am trying to use (via Thunderbolt) is Sata 3 – Could this ‘Negotiated Link Speed’ setting be my bottleneck and how would I adjust it to allow the full speed of Sata 3?

        I tried the EFI update and it said not compatible with my system but my boot rom is already: IM121.0047.B1F, the profiler already shows 6gbs as the link speed, my issue is the NEGOTIATED link speed setting which I think is capping my speed.

        Many Thanks


    2. Denis says:

      I have a 21.5′ 2.7GHz iMac 2011 with 1GB HDD, is it possible to install your SSD drive as a second one (does it have the interface inside) and avoid the fan speed problem? Also is it possible to boot from SSD instead of HDD in this type of configuration?

    3. jmw1480 says:

      Any update to when a TurnKey Upgrade Program may be available for the 2011 27″ iMac? I am deciding between buying the 2011 iMac 27″ 2.7 GHz i5 2500S processor and the 2010 iMac 27″ 3.2 GHz i3 550 processor (both stock, non-refurb). I like what I’ve read about the OWC SSD drives and think it’s the most reliable way for me to upgrade, so this really is one of my few remaining deciding points. Thanks!

    4. dale11833 says:

      I received my 27″ 2011 imac 3.4ghz 1tb hd I updated the software to 10.6.7 then downloaded the 1.6 firmware update and it said “not compatible with this system” Why am I receiving this message? Did the firmware update already when I did software update? please advise thank you

      • OWC Michael says:

        Check your system profiler, under Hardware Overview – Boot ROM version should show IM121.0047.B0A if the update was successful.

      • dale11833 says:

        Boot ROM version shows IM121.0047.B0A so i guess it’s installed already. thx.

    5. dale11833 says:

      say it’s not compatible… i have 2011 imac 3.4ghz i7 with system 10.6.7 2gb vram graphics card 1tb factory drive. What’s up? thx. Dale

    6. David Espinal says:

      hi grant , how many sata 3 port have both new imac 21.5 ( 2.5 & 2.7 Ghz )

    7. Romeo Mariano says:

      If an EFI update can upgrade the drives on a 2011 iMac to SATA 6 Gb/s, can another such update upgrade the DVD Bay SATA port on the MBP 2011 to 6Gb/s also????

      After all, both ports use the same chip. Perhaps Apple is throttling the speed down on the DVD SATA port just like it throttled down the second HD SATA port on the iMac 2011.

      I wonder if any of you can contact Phil Schiller to ask him about this?

      • OWC Michael says:

        The Z68 chipset the iMac utilizes has the capabilities of running two 6Gb/s SATA ports as well as an additional four 3Gb/s ports. It looks like the iMac has three total SATA ports and the EFI updater unlocked the 6Gb/s connection speed on the two ports which are capable of those speeds. The optical bay remains at 3Gb/s as it is a hardware limitation of the chipset itself.

    8. Jay says:

      Does the EFI update also allow for booting from external Thunderbolt drives?

      • OWC Michael says:

        Until we get our hands on a ThunderB enclosure in order to try the bootability….can’t really answer definitively.

        • Jay says:

          Thanks for your answer. What about a new Macbook Pro in Target Disk Mode over Thunderbold? Wouldn’t it act just like an external hdd/enclosure?

    9. A.D. says:

      The update for the 2011 Mabook Pro Has my computer running A lot cooler While watching Online Flash video. Would Anyone Like to test pre/post update temps?

    10. Matt says:

      Will there be a turnkey program for the 2011 21.5″ iMac?

      • OWC Grant says:

        Hey Matt….at this time we’re only considering the 27″….just like the 2010 model program. But never say never…we need more time with these new machines to truly determine future offerings.

    11. Jay says:

      Does the Firmware update also allow to boot from external Thunderbolt drives? Maybe you can try it with a new Macbook Pro in Target Disk Mode? External SSD with Thunderbolt would be great!

    12. Marc says:

      Given the nature of the problems with the 17″ MBP 6G port, I’m not expecting the updates to help, but it would be interesting to see if it makes a difference. I suppose if nobody else tries it in the next couple days, I’ll crack mine open again and move the SSD back to the HD bay to see if it fixed anything.

      I’d be more inclined to test, but the outside corner screw on the Data Doubler was apparently a little short or something, so it ended up stripping out when I tightened it, which has me nervous about removing the other two screws any more than I absolutely have to. You guys ever heard about problems with that in the past, or just me? (It could of course have been my gorilla grip over-tightening it, but I’ve only ever done that once, and I work with similar stuff professionally.)

    13. Jonathan says:

      Hi there!

      First of all, thanks for great products, great site, and great customer service! Loving my data doubler solution in my MBP so far.

      I have a question though! Is there any information on the new iMac 27 inchs, when it comes to if I would go and buy one with only a stock HDD (and no dual SSD solution), would it then be possible to expand it with a dual HDD+SDD solution using OWC harddrives?
      I know it was possible in the previous model (as per http://blog.macsales.com/6332-27”-mid-2010-imac-disassembled) but do we know already if the design is the same?

      Thanks and kind regards,


    14. Kenny Linhart says:

      I can’t wait to see how the Raid 0 with 6G in the iMac is going to turn out 1 Gb/s read and write now thats gonna be fast!!!!

    15. Jason says:

      Wow, amazing!

      On Barefeats, Rob-ART notes that replacing the internal drives causes the fans to run at full speed? Can you comment on this vis a vis potential OWC SSD upgrades?

      • OWC Grant says:

        Definitely something we’re looking into, Jason. We’d like to be as fast as our SSDs on some of these things….but with the new machines out just Tuesday…we do have to sleep and eat occasionally. ;-)

        As always, thanks for making us your news source and check back to see what solution we come up with.

    16. DCJ001 says:

      Since the article does not specifically mention it, does this update affect for the 21″ iMac along with the 27″ iMac?

      • OWC Grant says:

        Yes…sorry about that oversight….gives both models two SATA 3.0 channels…the main bay and SSD bay.

        • DCJ001 says:

          You said:

          “gives both models two SATA 3.0 channels…the main bay and SSD bay.”

          Did you mean to say:

          “gives both models two SATA 6.0 channels…the main bay and SSD bay.”

    17. Workboy says:

      Great! Now we know that the new imac 2011 has a SATA III of 6Gb/s interface, what drives Apple mount, of 3Gb/s or 6Gb/s, whether hard or solid state disks? What brand are the discs and have reference?

    18. Travis says:

      Excellent, thanks! Ordered my 6G!

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