2009 i7 27" iMac Hard Drive Upgrade...

Discussion in 'iMac' started by cmosq, Nov 1, 2010.

  1. cmosq macrumors newbie

    Aug 10, 2009
    Sorry for bringing this up again. Looking to upgrade the 1TB Seagate ST31000528ASQ drive that came in my 2009 27" i7 iMac to a 2TB or 3TB drive. Any known good successes out there? A success would be when:

    1. You used either the original temp cable that came with iMac or the LCD/Optical temp cables from applecomponents.com.

    2. HDD fan working properly afterward, meaning that the HDD fan will ramp up when temperature goes up and back down again to about 1100 RPM when the temp goes down. I don't think that shorting the cable is an acceptable solution but if you know it works...

    Please let me know which HDD/temp cable you used as well as the hard drive. I'd also like a drive which is not too noisy, my stock seagate is nearly silent.
  2. SpitUK macrumors 6502


    Mar 5, 2010
    East Yorkshire, UK
    I have a 2Tb Seagate drive in my iMac and its near silent. I shorted out the temp sensor with a staple and some tape. Works a treat.
  3. cmosq thread starter macrumors newbie

    Aug 10, 2009
    but does it really?

    I know about shorting the sensor and I see this as an OK answer for an SSD which doesn't really heat up much.

    I'm concerned about doing this for a hard drive. It does get hot and the fan needs to speed up to cool it down, shorting the sensor may bypass this. You can notice this if you run istat menus and the hard drive fan speeds up when it's temperature is hot. Right now at stock, my drive is 38C and the fan is at 1106RPM. Which Seagate hard drive did you get? An LP 5900 RPM or an XT 7200 RPM? is it loud? Thanks!
  4. SpitUK macrumors 6502


    Mar 5, 2010
    East Yorkshire, UK
    In my iMac I have a Patriot Inferno SSD and The Seagate LP 5900rpm. It runs near silent and I cannot see any temperature changes from the 1Tb.
  5. een1bhs macrumors newbie

    Mar 29, 2011
    No need to short sensor cable, this will allow the fan to adjust to temp changes stil

    Hi, for anyone having issues with a overactive fan due to the HDD temp sensor not working, or are thinking of shorting the temp sensor cable.

    I have created a program that will let you set a fan speed to HDD S.M.A.R.T temperature relationship.

    I made this as I was having the same issue having upgraded my HDD to a model that doesn't provide the correct temperature using the sensor cable.

    I started using smcFanControl with sleepwatcher but didn't like the manual setup and the fact I was limiting the fan speed no matter the HDD temperature. now thats not a problem.

    You can grab the software from


    Its heavily based on Fan Control, but has been modified for use with the iMac and the HDD Fan, and now reads HDD temp using S.M.A.R.T. It also controls the speed OK with the overactive fans.

    Hope this helps some of you. Let everyone and me know if it does.


  6. blueroom macrumors 603


    Feb 15, 2009
    Toronto, Canada
    It's an old thread but I recently bought a used 2009 iMac 27" and decided to drop my 180GB OCZ Vertex 2 into it. Runs great and the HDD fan is happy and quiet.


    1 removing the bezel is very easy, suction cups from the dollar store did the trick. The hard part is keeping it spotless during the install.

    2 I only removed the topmost cable attached to the LCD panel and simply tilted the panel up a few degrees. The HDD is exposed and a small Torx can easily remove the two screws that hold the HDD in place.

    3 The two wire thermal sensor (Seagate version) was simply shorted out with a length of short bare wire. Double sided tape holds it firmly to the chassis.

    4 You'll need a 2.5" to 3.5" bracket for your SSD. The black one that comes with the OCZ doesn't match up with standard 3.5" mounting holes.

    I had my older 50GB Vertex 2 laying around so back in the MacBook it went, it's plenty as I've moved most of my documents into the cloud and on a NAS. As long as I don't run Windows (Windows 7 is a beast, ~20-24GB for just the basic install)
    50GB is plenty.

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