Skip navigation

iMac: Cooling and Harddrive Questions

2606 Views 13 Replies Latest reply: Mar 14, 2011 4:45 PM by rkaufmann87 RSS
CMRLunatic Level 1 Level 1 (0 points)
Currently Being Moderated
Mar 10, 2011 6:38 AM
I have a 2010 21.5" iMac with a Hitachi drive.

I've always had an issue where the fans would, on occasion, ramp up and stay ramped up. The solution for this was always to turn the mac off, and turn it back on. The fans would not, no matter how long the mac was left alone, ramp back down.

Yesterday I replaced the stock Hitachi drive with a 2TB Hitachi drive. Installation went real well. The fans didn't ramp up until a prolonged period of heavy, heavy hard drive access (i.e. partitioning drive, recovering the system from my backup drive to the new drive, copying miscellaneous data from other external drives to the new drive...easily an hour of heavy use).

Curious, I left the system alone for the night with the fans ramped up. The next morning, they were still ramped up. This lead me at this point to assume a few possibilities:

1) The mac, once it gets hot enough to cause the fans to ramp up, has no mechanism for saying "Hey...everything's cool now...you can slow back down!"

2) The mac gets hot, and never gets cool enough for the fans to ramp back down. It seems to me that this shouldn't be the case especially in a situation where its not being used for a prolong period and goes into sleep mode...unless something is preventing it from going to sleep. I'm wondering if something is preventing the drive from powering down during sleep mode.

I'm guessing number two, because the next morning after doing the shut down/turn on that I've done so many times in the past, the fans stayed low for a while (maybe 30 minutes) then ramped back up again. This leads me to believe the system was still running hot.

My next step is going to be to clean the dust out of the system real good and look at istat/istatpro and smcfancontrol. I'm thinking that the minimum fan speed should possibly be higher. Can anyone suggest recommended heat ranges I should be looking at?

Also, are there any aftermarket solutions or fan replacements that anyone has experimented with?

Message was edited by: CMRLunatic
iMac, Mac OS X (10.6.4), N/A
  • rkaufmann87 Level 8 Level 8 (40,745 points)
    Currently Being Moderated
    Mar 10, 2011 6:51 AM (in response to CMRLunatic)
    I suspect your machine only needed a SMC reset, this usually calms down fans. Also iMac's do run warm however they are designed to shut down if they sense they are beginning to overheat.

    Also I hope you did some research into which HD's work properly in your iMac. I believe the 2010 & 2011 machine need HD's that have integrated heat sensors in them. Prior to 2010 the HD's Apple put in iMacs used an external heat sensor held on by glue. With the later machines they dropped the external sensor and went to internal sensor's. The result being if you change the HD you MUST get one specifically designed for the iMac or it will not be cooled they way it should be. I would STRONGLY recommend you research the 2TB Hitachi you installed.

    And finally if you had AppleCare or any remaining warranty there is a chance it is void now.

    Roger
    iMac 6 GB RAM, MacBook Air 4GB, 128GB SSD, Mac OS X (10.6.6), iPhone 3GS Airport Extreme Airport Express
  • rkaufmann87 Level 8 Level 8 (40,745 points)
    Currently Being Moderated
    Mar 10, 2011 7:20 AM (in response to CMRLunatic)
    OK, I haven't changed a HD in one of those so I'm not sure exactly what the connections look like.

    If you haven't already do a SMC reset, that may be all that's needed to settle your fans down.

    _SMC RESET_

    • Shut down the computer.
    • Unplug the computer's power cord and all peripherals.
    • Press and hold the power button for 5 seconds.
    • Release the power button.
    • Attach the computers power cable.
    • Press the power button to turn on the computer.

    _PRAM RESET_

    • Shut down the computer.
    • Locate the following keys on the keyboard: Command, Option, P, and R. You will need to hold these keys down simultaneously in step 4.
    • Turn on the computer.
    • Press and hold the Command-Option-P-R keys. You must press this key combination before the gray screen appears.
    • Hold the keys down until the computer restarts and you hear the startup sound for the second time.
    Release the keys.
    iMac 6 GB RAM, MacBook Air 4GB, 128GB SSD, Mac OS X (10.6.6), iPhone 3GS Airport Extreme Airport Express
  • rkaufmann87 Level 8 Level 8 (40,745 points)
    Currently Being Moderated
    Mar 10, 2011 9:32 AM (in response to CMRLunatic)
    I really can't comment about that. You may want to talk to an AASP about that, it wouldn't hurt that's for sure.
    iMac 6 GB RAM, MacBook Air 4GB, 128GB SSD, Mac OS X (10.6.6), iPhone 3GS Airport Extreme Airport Express
  • FangSuede Level 4 Level 4 (2,195 points)
    Currently Being Moderated
    Mar 11, 2011 6:56 PM (in response to CMRLunatic)
    I have a July 2010 21.5" iMac i3 3.2GHz w/5670, 12GB RAM, 1TB Seagate HDD.
    It was getting a little hot playing advanced gaming when the ambient room temperature is above 72F. I feel 160-180F (viewing with Hardware Monitor) is too hot for this machine's longevity.
    The iMac sits in a poorly ventilated cabinet so I've added the fan controller software that you mentioned - smcFanControl 2.2.2.

    I set the fan controller pref's for Gaming and click it on just before I start.
    My Gaming (maximum effort) setting makes the three fans (CPU/HDD/OD) run at 2200 RPM minimum.
    What a difference! Max temps are now in the 140F range after a bout of gaming, much better.
    When I don't need the fan software (most of the time) I just turn it off, easy.

    You'd think that Apple would have fan controllers that work to alleviate any potential overheat better than they do. I don't like using 3rd party software but in this case it does the job.
    •iMac '10 21.5, , i3-3.2GHz •Cube Dual 1.7GHz, ATI 9800w/10.5.8, Mac OS X (10.6.6), ..and various other Mac's
  • rkaufmann87 Level 8 Level 8 (40,745 points)
    Currently Being Moderated
    Mar 11, 2011 9:37 PM (in response to FangSuede)
    The iMac sits in a poorly ventilated cabinet.....



    That is your problem right there, not your computer or it's design but the lack of circulating air around it, in other words you caused the situation not Apple. Change that situation then re-***** the temperatures it's operating at.
    iMac 6 GB RAM, MacBook Air 4GB, 128GB SSD, Mac OS X (10.6.6), iPhone 3GS Airport Extreme Airport Express
  • FangSuede Level 4 Level 4 (2,195 points)
    Currently Being Moderated
    Mar 11, 2011 10:03 PM (in response to rkaufmann87)
    Chuckle..... having written that you'd think it would be obvious to me, sigh.
    Not having had the cabinet nor the iMac very long I'm learning that you may be right. I'll think on providing better air circulation in that area and see what happens. Meanwhile, the fan controller works as a stopgap.
    As Han Solo once said, "Sometimes I amaze even myself".
    •iMac '10 21.5, i3-3.2GHz •Cube Dual 1.7GHz, ATI 9800w/10.5.8, Mac OS X (10.6.6), ..and various other Mac's
  • WZZZ Level 6 Level 6 (11,900 points)
    Currently Being Moderated
    Mar 14, 2011 9:37 AM (in response to rkaufmann87)
    (CMRLunatic: unless you can cleanly remove it leaving not a trace, by installing your own after market fan, you have probably jeopardized your warranty. And, if you drill through the back, your warranty is definitely toast.)

    rkaufmann87 wrote: Also I hope you did some research into which HD's work properly in your iMac. I believe the 2010 & 2011 machine need HD's that have integrated heat sensors in them. Prior to 2010 the HD's Apple put in iMacs used an external heat sensor held on by glue.


    Roger, just to get this out here for general information. From OWC:

    Fortunately, you can reuse the cable that came with your iMac as long as you replace the drive with another model from the same manufacturer we have confirmed works properly with this thermal sensor cable.


    That means, in order to upgrade the internal drive, you need to have a connector cable that’s compatible with the brand of drive that you’re installing… and that’s an Apple service part not generally available to the end user.


    http://blog.macsales.com/2751-proprietary-cable-can-put-the-brakes-on-upgrading- late-09-imacs

    Looks like some of the cables are available here

    Interestingly, I changed the drive in my old G3 some years ago from the original Maxtor 10GB to a Seagate 160GB. The Maxtor had no external sensor (it may have had a built-in sensor; I never checked,) but the Seagate has a built-in sensor. And connected through the original data cable, it is showing a temp readout -- the only sensor reading of any kind on the G3. It seems many, if not most, drives have a built-in sensor.
    iMac 21.5" 10.6.5, iMac G3/400 10.4.11
  • rkaufmann87 Level 8 Level 8 (40,745 points)
    Currently Being Moderated
    Mar 14, 2011 4:45 PM (in response to WZZZ)
    Thank you!
    iMac 6 GB RAM, MacBook Air 4GB, 128GB SSD, Mac OS X (10.6.6), iPhone 3GS Airport Extreme Airport Express

Actions

More Like This

  • Retrieving data ...

Bookmarked By (0)

Legend

  • This solved my question - 10 points
  • This helped me - 5 points
This site contains user submitted content, comments and opinions and is for informational purposes only. Apple disclaims any and all liability for the acts, omissions and conduct of any third parties in connection with or related to your use of the site. All postings and use of the content on this site are subject to the Apple Support Communities Terms of Use.