Picking the right hybrid for a 2009 iMac 27"

Discussion in 'iMac' started by JPamplin, Aug 26, 2014.

  1. JPamplin macrumors 6502


    Mar 12, 2009
    Nashville, TN

    I thought I was getting a good deal on CL when I bought a 27" iMac 2.66 i5 for $450. But when I got it home (no way to test during exchange) I found out:

    • Fans are stuck on full speed
    • 3.5 inch HD has been replaced with a 2.5 laptop drive

    It's apparent to me the reason the fans are stuck on HIGH is that there's a temperature sensor that is plugged into the stock 3.5 inch drive (a WD, I think). Since there's a laptop drive in there now, the cable was ignored.

    So I need to shop for a 3.5 inch HD (preferably hybrid) that will fit the 2009 iMac sensor connector. Anyone have recommendations on which one to get? I feel so dirty getting this thing without plugging it in, but it's my problem now.

    Thanks in advance,

  2. Kyle-K, Aug 27, 2014
    Last edited: Sep 17, 2014

    Kyle-K macrumors regular


    Aug 23, 2014
    Geraldton, Western Australia.
    That's expected with a non stock Apple Hard Drive. See below.

    Drive size actually doesn't matter is the drive in a 2.5 to 3.5 adapter?

    It sounds like the previous owner use software to correct the fan issue, Which was most likely removed if they did a clean install before selling. If they didn't have a look in the applications folder it may still be there but not running.

    You can do the same if you wish to continue using the current drive or if you wish to use another brand from what was in their originally.

    The good news is these models didn't have custom firmware so replacing the drive that you currently have with one from the Manufacturer that was originally in the iMac should solve the issue.

    While later models of iMacs have external temperature sensors that can be purchased and install to solve the issue this model doesn't.

    You may be able to source the temperature sensor cable for the brand you want from a part supplier online if you wish to change brands in the late 2009 iMac.

    Now to the important bits identifying which sensor cable you have so you know which manufacturer you need to purchase your hard drive from.

    The picture at the top of this post will show you which cable is for what and this post on the OWC website may shed some more light on this for you.

    See above for the relevant information and see below for my recommendation.

    One I don't think you're going to get a hybrid drive to work or just a standard SSD to work without using the software mentioned above.

    Some options.

    1. Replace the drive with a 3.5 spinning drive from the correct manufacturer that your sensor cable is for in the capacity that takes you fancy the most.

    2. Do what I mentioned above but also replace the optical drive with a second hard drive, Requires an adapter you could also use an SSD or use the 2.5 drive that was present originally. If you choose this option you can only replace the optical drive with a drive that is a 2.5 form factor.

    See here for the relevant part, to replace the optical drive.

    E.g. A 4 TB or larger 3.5 hard drive, and have an SSD up to 1 TB in the optical drive bay. large data files on spinning drive operating system on SSD for example.

    3. If you're running a later version of OS X for example Mavericks you could choose to roll your own fusion drive.

    By following option to if the 3.5 hard drive is 4 TB or less you probably only need a SSD in size of 128 GB larger than 4 TB you probably may want to look at a 256 GB SSD. Instructions on how to roll your own fusion drive can easily be found with a simple search.

    At the end of the day really depends on how much money you want to spend on upgrades more RAM is also good.
  3. p3ntyne macrumors 6502


    Jan 10, 2014
    Sydney, Australia
    I believe only the original HDD has the temperature sensor cable.

    If you do not want to deal with the fan issues, I suggest you pick up the a stock HDD (spare part from EBay or similar) and install a SSD.

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