27 iMac 2011 Graphics card upgrade 6990m

Discussion in 'iMac' started by All Taken, Apr 12, 2012.

  1. All Taken, Apr 12, 2012
    Last edited: Apr 12, 2012

    All Taken macrumors 6502a

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    #1
    I'm looking to upgrade my 27" 2011 i5 6770m 512mb to a 6970m 2GB. This is entirely possible with the available Apple service part but I was thinking and would really love a detailed answer.

    Could I install a 6990m? I'm aware Apple don't supply a iMac with this card but i'm pretty sure I read somewhere that Lion has support for all Radeon 6 series cards (could be wrong) If it does support it without EFI flashing then great. If not could I perhaps use a flash from a 6990 desktop possibly Mac Pro card that somebody has done on here???

    Really need some intelligent answers on this, not the usual 'You should have purchased the higher model anyway', 'You can't upgrade the graphics' and Seems like a lot of work for not much gain.

    Thank you.
     
  2. Johnf1285 macrumors 6502a

    Johnf1285

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    #2
    I guess something that needs considering is whether or not the mobile gpu used currently in the 27" is the same form factor of 6990m's found in PC laptops. But when I say same form factor I'm also referring to whether or not the heat sinks found on Apple's 6970m would be compatible to attach to a 6990m. Then power requirements and TDP needed, as well as the drivers, ect., all need to be thought about.

    Otherwise beyond removing your existing card, inserting a 6990m with Apple's heat sink, connecting a thermal sensor, it's all set - almost plug and play if heat/power/drivers/form factor all work in your favor
     
  3. BigJohno macrumors 65816

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    #3
    Seems like a lot of work for not much gain....
     
  4. All Taken thread starter macrumors 6502a

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    #4
    Seems like a pointless reply
     
  5. Tyrone Chicken macrumors newbie

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    Apr 15, 2012
    #5
    there is a pretty big difference in performance between a 6970m and a 6990m

    but as far as i know osx doesn't support the 6990m considering they don't have any models with it
     
  6. leman macrumors 604

    Joined:
    Oct 14, 2008
    #6
    Well, 6990M is an underclocked Radeon 6870 and 6970M is an underclocked Radeon 6850. The only difference between the cards is the number of shader cores. No idea if the number of cores is hard-coded in the driver. There is a possibility that the card will work nicely as it is, or maybe with an injector. Netkas reports that OS X drivers seem to natively work with the 6870. By no means should you flash that card with the desktop's 6990 firmware, you will surely destroy it!

    So, if you are rich, than get the card,put it in and see whether the system boots. It might ;)
     
  7. All Taken thread starter macrumors 6502a

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    #7
    Tempted, so tempted. Seems like a lot of work for not much gain though.
     
  8. leman macrumors 604

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    Oct 14, 2008
    #8
    I thought you considered that a pointless reply :p

    P.S. BTW, another things which is probably more important is the cooling system consideration. The iMac is already designed on the limit of thermal engineering. There is a good chance that a more powerful GPU could send your whole system smoking...
     
  9. All Taken thread starter macrumors 6502a

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    #9
    :p I considered this as i'm stuck at the thermal barrier first before anything else matters. I would say the card is thermally acceptable to the heat sinks and surrounding tech. My logic is that Alienware laptops contain this card and have much more surrounding constriction, less airflow, and smaller heatsinks.

    Apple have been releasing faster cards with perhaps a higher heat to power ratio at iMac refresh but the design remains the same. Would anyone with Mac Pro experience care to weigh in on compatibility here?
     
  10. Intell macrumors P6

    Intell

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    #10
    Aluminum iMacs actually have very good cooling. They always feel hot because their bodies are designed to act as a giant passive heatsink. Plus it has three fans that usually only idle. The fans can an do rev up if heat becomes a consern, but it rarely does. Apple's other iMacs from the G4 to the white Intell had a much lower heat tolerance, with the G5 having known overheating problems.
     
  11. All Taken thread starter macrumors 6502a

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    #11
    Exactly my thinking, my guess is Apple will introduce a hotter card at the coming refresh but the fan, heatsink placement and case design will remain the same.

    Any thoughts to compatibility?
     
  12. All Taken thread starter macrumors 6502a

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