2011 iMac Graphics Card Upgrade

Discussion in 'iMac' started by MichaelDT, Jun 14, 2013.

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  1. MichaelDT, Jun 14, 2013
    Last edited by highvoltage12v: May 31, 2019

    MichaelDT macrumors regular

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    #1
    General questions
    Q: What new issues will I have after swapping my card with a PC MXM card?
    A: The two biggest issues we have are:
    1. The loss of EFI boot screen*
    2. The loss of Backlight control**
    3. You can only connect one external monitor to the 27" iMacs

    Q: What paste is recommended to cover the VRAM/Components on the MXM card like Apple’s design?
    A: For the GPU Die any thermal Paste like Thermal Grizzly’s Kryonaut paste is good for the Die. For onboard components I recommend using K5 Pro Viscous paste instead of thermal pads, due to the unevenness of the heatsink, it’s also similar to Apple’s original Design: https://www.amazon.com/gp/product/B00K04D3UK/

    Q: Why aren’t you using Maxwell or Pascal cards in the iMac?
    A: A lot of people here have tested Maxwell cards with their 2011 iMacs, and have had various issues from no internal display, no backlight on internal display and the card not hitting boost. It is best not to attempt using Maxwell cards until we know of a VBIOS that will play nice with the iMac and the “Dying light” brightness control module is perfected.

    2009-2011 27” iMac MXM card upgrade Q/A

    Q: What MXM cards are known working?
    A: Currently the Dell/Alienware 765m, 770m, 780m and 860M are confirmed working. You could also use the smaller form-factor(MXM 3.0A) Dell K2000M card.

    Q: What mods are needed for the 27” iMac to make the cards fit into the iMac?
    A: There are 2 mods needed to make the MXM card fit. First you must grind down your heatsink in the area where two large coils sit, this way the card will sit flush with the heatsink. Second you must drill out the rivets on Dell’s X-Clamp or grind away Apple’s X-Clamp so no capacitors or components touch the X-Clamp or sit under it. Skipping this step can fry/damage your card.

    2010-2011 iMac 21.5" iMac MXM card upgrade Q/A
    Q: What MXM card(s) are known working?
    A: currently only the Dell K2000M is the preferred MXM card to swap due to space issues and low power draw of the k2000m.

    Q: are there any internal modifications needed for an MXM-A swap?
    For an MXM-A swap (the shorter/less power draw cards) there are no modifications that are needed for the heatsink. The X-clamp needs be removed from the back of the card and have the screw posts drilled out.

    Installing macOS Mojave
    Since you will have a Mojave compatible GPU, you could run the newest macOS without any serious issues. The recommended method is to have High Sierra as your primary OS and install Mojave alongside on a separate partition. So if anything goes wrong, you can still boot back into High Sierra to fix issues. You could preinstall Mojave before changing your GPU. Use dosdude1's Mojave patcher to do the install: http://dosdude1.com/mojave/
    Important: while running the Post Install tool, make sure you deselect the Legacy Video Card patch option(since you will using a new, compatible card).

    * This means that when you start your iMac, you will have a blank screen until macOS boots up. So you cannot see the boot menu and the Apple logo during boot. The boot menu still works, so you can navigate it blindly if you are lucky.

    Q: sleep is broken in Mojave, how do i fix this?

    A: this is because of the SandyBridge kexts missing in Mojave. Although we aren't using the iGPU, these kexts are still needed for proper sleep functionality. A zip file is attached with the proper kexts to restore sleep in Mojave. Inside the unzipped folder contains an APP, Kext Utility and the necessary SandyBridge kexts needed to be installed. Right click to open kext utility, then immediately quit. Select all the files inside the folder and drag them on top of kext utility and allow them to install.


    ** An attempt is being made throughout this thread to fix Backlight. A "Dying Light" module created by @dosdude1, originally intended for the 2011 15” MacBook Pro has been found to work with controlling the backlight PWM signal on the iMac. This involves removing your SD card board, splicing wires and soldering to the SD card adapter. Currently no official guide is made for this mod, so it is briefly mentioned here. You can also try a software based method, which can simulate the brightness change(it will just change the colors appearing on your screen, not the actual backlight). The best app for this is Brightness Slider, which is available on the App Store for free.

    Original Post from @MichaelDT June 14th, 2013.
    I will be attempting to upgrade the MXM card in my 2011 21.5 iMac from the factory 6770m 512mb to a NVidia 675m 2GB. I choose this card because the chipset already has support from 10.8.3 onwards and affordability for an experiment. I am hoping that it will work without flashing like many of the other non MXM modern graphics cards (UEFI support) do in 64bit EFI Mac Pros ( I may loose the initial boot screen). But if all else fails I will attempt a flash. I will report back my findings when the card arrives (from Hong Kong). Wish me luck hopefully this will give those of us with the last modular iMac a path forward.
     

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  2. SpeedFleX macrumors 6502

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    #2
    Good luck brave sir!
     
  3. cmanderson macrumors regular

    cmanderson

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    May 20, 2013
    #3
    Let us know how it goes, and if it works for you, what sacrifices you've had to make, if any. Also, links or contact info to your resource in HK.
     
  4. cybert macrumors newbie

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    Jun 13, 2012
    #4
    Yes please do keep us posted!
    I want to do the same thing.
     
  5. MichaelDT, Jun 19, 2013
    Last edited: Jun 19, 2013

    MichaelDT thread starter macrumors regular

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    #5
    Excellent news it is exactly as I suspected, you simply need an mxm a/b card that supports UEFI. I did loose my initial boot screen but once OSX loads the screen powers up. So initially I ordered the 675m but when I received that card it had BIOS only drivers...so I ordered a DELL/Alienware 680M off ebay. Only Trouble so far is it isn't recognizing my second display, but I'll tinker and we shall see if I can fix that.:)

    Edit: So looking at my console logs it senses the second display then drops it, I'm thinking it is the driver.
     

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  6. MichaelDT thread starter macrumors regular

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    #6
    More details: If you use an MXM-B card it will be larger than the MXM-A card that the ATI is; so it will hang over the HDD. It doesn't cause any issues though, no modifications needed. During the install the heatsink from the ATI 6770M is a just a tiny bit too small, half of one of the ram chips will be uncovered. This doesn't seem to be a big deal as it is the chip positioned closest to HDD fan and I have been monitoring the heat sensors and they don't seem an higher that with the ATI card even playing graphics intensive games.
     
  7. Jonez1 macrumors newbie

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  8. MichaelDT thread starter macrumors regular

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    #8
    No, I will take it apart tomorrow after I get home from work and take some photos to show what the install looks like vs. stock for those that are curious.
     
  9. MichaelDT thread starter macrumors regular

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    Aug 18, 2012
    #9
    Well I have got my second display working, the Nvidia 680M card does not like the Minidisplay to HDMI adaptor I was using, I switched to a VGA and it powered up.
     
  10. QCassidy352 macrumors G4

    QCassidy352

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    #10
    Well done sir!! Very nice. Wish I had the guts to do this to my 2011 21.5". You'll have to give us some performance numbers when you get a chance to play around with it. :)
     
  11. MichaelDT thread starter macrumors regular

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    #11
    Some photos, comparing the stock MXM-A card to an MXM-B card and pictures of the MXM-B card installed.
     

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  12. QCassidy352 macrumors G4

    QCassidy352

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    #12
    Thanks for the pics. That's outstanding. Your imac is a beast and a half now.
     
  13. kgian macrumors regular

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    Jul 17, 2011
    #13
    Congratulations!
    How can you boot to windows bootcamp if you lost the bootscreen?

    Also, can you post a link to the mxm board you baught?
     
  14. MichaelDT thread starter macrumors regular

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    Aug 18, 2012
    #14
    Concerning bootcamp etc see this thread The concept is just the same, only instead of standard PCI iMacs use NVidias MXM 3.0 protocol which really is just PCIe anyways.
     
  15. QCassidy352 macrumors G4

    QCassidy352

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    Bay Area
  16. goodcore macrumors newbie

    goodcore

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    #16
    Hello MichaelDT!
    Thank's for your research
    I also trought with replacing graphic card in my iMac 27 over my factory 6970M. But i want install 7970M. Keep in touch.

    Vasily
     
  17. StevieRay macrumors newbie

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    Jun 24, 2013
    #17
    This may be a dumb question, but can you swap the video card on a 15" MBP (non retina) like this, or is it soldered to the MB?
     
  18. goodcore macrumors newbie

    goodcore

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    #18
    It's soldered to MB. You can see here on step 12.
     
  19. mikeylam macrumors newbie

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    Jul 12, 2013
    #19
    Hi Michael, I am a bit confused by the below. What do you mean by "So initially I ordered the 675m but when I received that card it had BIOS only drivers...so I ordered a DELL/Alienware 680M off ebay."?? I would think if you install the 675M into the system, OSX should just load the driver automatically? Why would the card come with OSX drivers as they are PC cards anyway?

     
  20. Commy1 macrumors 6502a

    Commy1

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    Feb 25, 2013
    #20
    That's an impressive upgrade, I'm impressed. Are there any heat issue? or even noticeable higher temps? The 680 is a beast card, I wouldn't be comfortable putting it inside such a confined space, but if it works, why the heck not.
     
  21. omvs macrumors 6502

    Joined:
    May 15, 2011
    #21
    Is there any way to get the boot-screen? I was excited and ordered a 680M, though now I'm wondering if this means I won't be able to boot with File Vault enabled....

    I did see some posts about updating the firmware to get EFI for win8, but it sounds like your card has the EFI firmware update and still gives no boot screen?
     
  22. pastrychef macrumors 601

    pastrychef

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    Location:
    New York City, NY
    #22
    Nice job! It may be possible to get back boot screen image if someone with an iMac that came with a GTX 675MX gives you an image of the ROM.

    You mentioned that the stock heatsink is too small and leaves some of the VRAM exposed. I don't know if theres, enough room, but you can try some of these:
     

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  23. zerozoneice macrumors regular

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    #23
  24. iSayuSay macrumors 68040

    iSayuSay

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    #24
  25. jezzy macrumors member

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    Location:
    Montreal, Quebec
    #25
    Very brave. Thanks for sharing! I'm personally looking at upgrading my iMac mid 2010 27" 5750 1gb to a 2011 6750 card.. But can't swallow a 600$ price tag!
     
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