2011 iMac Hard Drive Upgrade, Fan Issues

Discussion in 'iMac' started by ChargedPC, May 5, 2011.

  1. macrumors member

    May 3, 2011
    Well it looks like we're back to last years problem:

    Upgrade the hard drive in your iMac and the hard drive fan revs up to full speed...

    SMCFanControl is always a possible solution, but we'd prefer something hardware based :)

    In previous generations, all it took was reversing the leads on the temperature sensor (because apple's firmware on their hard drives reversed the pins), but now there is no temperature sensor attached!

    We replaced our Seagate Barracuda 1TB (Firmware AP4C) with a Barracuda LP 2TB.

  2. macrumors newbie

    Jan 30, 2008
    I'd love to hear from other people who swapped out drives, but I swapped out the main HD and replaced it with a SSD on my new i7 iMac and there doesn't seem to be any issue with the temp sensor. The fan right now is running at 1096rpm.

    I noticed the new ones did not have a sensor attached to the drive anymore, but I also couldn't tell where they put the sensor in the new ones.
  3. thread starter macrumors member

    May 3, 2011
    Mind telling us what type of SSD you installed? Also assuming you swapped it with the old HD instead of adding it to an SSD bay?
  4. macrumors newbie

    Jan 30, 2008
    It is a OCZ Vertex 2. It is a 3.5 inch drive so I just swapped out the old hard drive for the new SSD. I am not sure how changing the HD in your case would affect the fans since you don't mess with the temp probe any more. Is it possible it might have been accidentally disconnected causing the fans to run wild like in the old revisions?
  5. thread starter macrumors member

    May 3, 2011
    There was definitely no HDD temperature probe connected when we removed the old hard drive. Our suspicions lie with the custom Apple firmware on the Seagate HDD, but we're really not sure at this point. We hope to try connecting to one of the other SATA ports to see if it's maybe a problem only with the main SATA connector (maybe temp data is being passed through form the hard drive directly through the data cable).
  6. macrumors newbie

    Jul 18, 2010
    I guess apple is using the SMART temperatur information over the sata bus now - but due the diff firmware in a diff format.

    And "normal" SSDs don't have any temperatur sensor at all, only enterprise SSD show one.

    That's worst than 2010 ! :mad:
  7. macrumors 68020


    Apr 6, 2009
    wow you guys already opened up your new imacs ?
  8. macrumors newbie

    Dec 7, 2010
    I ordered an imac BTO with almost everything, and i have added previous gen imacs to HDD+SSD and i wonder if anyone tried or can confirm this is not possible with this version.
    I have a Intel 510 SSD waiting to install on this imac, and in the past if i did that it required jumping the temp sensor to keep the fans at a decent speed, is this still required with the new imacs?
  9. macrumors 6502a

    Jun 10, 2009
    Apple... Should have installed better storage by default. Like say 3tb
  10. macrumors 603


    Oct 13, 2008
    Everywhere And Nowhere
  11. macrumors newbie

    May 11, 2011
    Colorado Springs, CO
    We have a 2011 iMac 21.5" in the shop that the customer needs to operate without the HD installed for security reasons (external drives fit in a safe better than iMacs... :) ). In the past we just jumpered the thermal sensor, but the new ones are (as mentioned above) run through the SATA data cable instead.

    In testing, instead of ramping to full speed, the fans go to ~2000 RPM with no HD installed. We also tested with a 1TB WD Caviar Black drive that is 1 year old and it behaved the exact same way. At half speed, the unit is acoustically acceptable, but still noisy compared to a standard unit.

  12. macrumors newbie

    May 11, 2011
    I got the same problem over here. Today I got my 27" iMac with the 2.7Ghz i5, 4GB RAM and the 2GB Graphics Card.

    I replaced the original Western Digital Caviar Black with my brandnew Intel 510 Series with 120GB. I first noticed the noise at the installation but thought it was due to some incomplete installation or driver issues. But after the installation and my TimeMachine Migration the noise was still high. So I checked the HDD Fan and it was running at about 4000 rpms. So, again, I thought that it maybe would be a driver issue. But after the installation of the latest software the fan even got worse. It was now turning at a full 5600 rpms. I couldn't even listen to music anymore.

    After researching the issue I landed here. The main problem for me is that I can't even limit the fan speed. I wouldn't care about the whole issue if I could just limit the fan, because I'm pretty sure that my SSD doesn't need any cooling.

    And now, I just don't know what do do, but I need this machine for work.
  13. thread starter macrumors member

    May 3, 2011
    Joe it seems you need something internal to keep the thermal sensor happy. Perhaps leaving the original drive in and just keeping it blank, or using a small 8GB SSD just to keep the thermal sensor at bay. There must be a way to do this, because Apple certainly has iMacs with just the SSD installed, although there's probably nothing installed in SATA0. Maybe just unplugging the SATA cords from the motherboard?

    A non-ideal but workable solution for both of you would be to use SMCfancontrol (google search and it's a free download). You can set it to control your hard drive fan and that will keep it at bay.

    Also it seems certain SSDs do not cause the thermal sensor to rev the fans. We've installed an OCZ Vertex 3 and our fans never rise above 1500 rpm (although ideally we would still have them sit comfortably at 1100rpm).
  14. slackie, May 11, 2011
    Last edited: May 11, 2011

    macrumors newbie

    Apr 5, 2009
    As I stated out in another post - if you exchange your regular HDD with a single SSD using the SSD SATA port, then you MUST short out the HDD power and use SSD power port. Otherwise your fan will go turbo.

    This goes for all mid 2011 imacs.
  15. macrumors 6502

    Sep 13, 2006
    http://blog.macsales.com/10146-apple-further-restricts-upgrade-options-on-new-imacs OWC posted something just now about this issue, with some details.

    I started another thread on it before I noticed this one was talking about the same issue.
  16. macrumors 603


    Oct 13, 2008
    Everywhere And Nowhere
  17. macrumors 6502a

    Dark Dragoon

    Jul 28, 2006
    That article doesn't seem to make complete sense to me. Specifically this part:-

    A standard SATA power connector has 15 pins (sata-power pinout).
    A standard SATA data connector has 7 pins (sata-power pinout).
    In ifixit's teardown photos step 7 the pin counts are as expected, with 7 for data and 15 for the power connector.

    The only 4 pin connector on a SATA hard drive should be the legacy molex power connector which has been/is being phased out, and was there so that older PSU's which don't have a SATA power connector can still power the drive without an adapter.

    This isn't to say that it's down to the drive having custom firmware to report the temperature, but the physical connectors appear the same to me.
  18. macrumors 603


    Apr 13, 2010
    People please get your t-bolt money ready.

    It seems to me that t-bolt storage/boot drive and a program to keep the internal hdd spun down except for making a clone of the t-bolt drive will be a choice for some.
  19. macrumors 6502a

    Feb 16, 2011
    Apple moving back to proprietary hardware which will, in the end, slow its growth. This is why large companies will not move towards Apple Products. If they want to void the warranty on an upgraded system, then do so, but to prevent any maintenance from being done even after the warranty period, it just arrogant, controlling, and it's why it took me years to become an Apple fan. Disappointing for sure!
  20. slackie, May 12, 2011
    Last edited: May 16, 2011

    macrumors newbie

    Apr 5, 2009
  21. macrumors 6502a

    Jun 10, 2009
    This is mildyl alarming and I hope this can be resolved soon. I plan to crack open my iMac after a year's time to install a 3TB or larger drive + SSD.
  22. macrumors regular

    Oct 22, 2010
    I hope all of you will forgive a newbie's question:

    From the OWC Blog article, it sounds as if it's only trying to switch the hard drive itself that causes the problem; leaving the original hard drive in its bay, and adding an SSD to the other bay (which both 21.5 and 27 iMacs have, if I understand this properly) is fine.

    Is that right? So it's possible to modify the 2011 iMac yourself, as long as you don't mind a combination drive system?

    Thanks for your help!
  23. macrumors member

    Mar 8, 2007
    I think you got the solution there. Why are people ignoring your posts? LOL. But where do you get that plug that short out the HDD power?
  24. macrumors 68000

    May 6, 2004
    Sounds correct.
  25. macrumors member

    May 7, 2011
    Anaheim, CA

    This kind of pisses me off, Apple could at least allow us to choose what hard drive we want...??? Right?

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