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Lost Heaven

macrumors newbie
Jan 24, 2016
23
9
London, UK
Hello all,

I've been following this thread for months with great interest, as I've been considering attempting a GPU upgrade on my 27-inch, mid 2011 iMac for some time. However, this has now become a necessity, as its current one (a 6970M) seems to have stopped working (garbled image, seems to crash during boot, can't even access it from my MacBook via Screen Sharing).

I have some experience taking computers apart, so I'm not too intimidated about the process. I am, however, scared about the prospect of buying a GPU that will not work, so I just need to clarify some things:
  1. after reading all 15 pages of the thread, it seems the 780M seems to have had the most success cases. Can anyone be kind enough to tell me what I should look for when buying one? The simple fact that there are both green and blue coloured models freaks me out.
  2. just to triple check on this: saying that the boot screen is gone, simply means that it is no longer visible, but it's still possible to operate it blindly, right? If one has Boot Camp installed, it's still possible to boot into Windows by pressing Option, Right and Return, correct?
As a side note, I think it's a great shame that @MacVidCards is yet to find someone who's able to provide him with a space to do his magic. There's an opportunity here to offer an exclusive service to iMac owners who are now starting to consider ways to upgrade their systems. Also consider the fact that the 4 year period Apple offered to replace defective GPUs on mid 2011 systems is now running out, making the demand for such a service even greater.
 

VicLev

macrumors member
Jun 6, 2013
37
3
Since this iMac has a soldered GPU I don't know if it even has a EEPROM for storing VBIOS and EFI. This might also be stored somewhere inside the iMacs Bootrom like they do with the 2013 MacPro.

i remeber you were saying something about some information in the vbios concerning the first display intializtion been LVDS or EDP. can that be changed?

as far as i understand: regular laptop 780m cards have first output set to LVDS, could that be the issue for having boot menu not visible at the start?
 

MacVidCards

Suspended
Nov 17, 2008
6,096
1,056
Hollywood, CA
No, the lack of boot screen is due 100% to not having Mac EFI on the cards.

I have been offering for quite some time to work with someone to create a better iMac GPU card, I am 90% certain I could write an EFI that would at least enable boot screen, and possibly brightness control as well. I know how, I know the roms and the display mapping. What I don't have is an iMac or the space and time to take apart, etc. My prior posts in this thread spell it all out.

Any Nvidia card that has been shown to work in OSX is a good candidate. Some people here have done some of the hard work already.

Florian is a clever guy, but hasn't spent as much time immersed in Mac EFI.
 
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Synchro3

macrumors 68000
Jan 12, 2014
1,987
850
No, the lack of boot screen is due 100% to not having Mac EFI on the cards.

I have been offering for quite some time to work with someone to create a better iMac GPU card, I am 90% certain I could write an EFI that would at least enable boot screen, and possibly brightness control as well. I know how, I know the roms and the display mapping. What I don't have is an iMac or the space and time to take apart, etc. My prior posts in this thread spell it all out.

Any Nvidia card that has been shown to work in OSX is a good candidate. Some people here have done some of the hard work already.

Florian is a clever guy, but hasn't spent as much time immersed in Mac EFI.

The GTX 780M is a MXM 3.0 (b) card. These adapters could work in a Mac Pro for flashing:
http://www.liantec.com/product/TBM-1630.htm
http://www.zentrica.com/product/mxm-3-0-to-pci-express-carrier-board-type-1/

Installing the card in the iMac is buyer's work on-site.
 
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Fl0r!an

macrumors 6502a
Aug 14, 2007
909
530
as far as i understand: regular laptop 780m cards have first output set to LVDS, could that be the issue for having boot menu not visible at the start?
If I recall correctly, your GTX 780 didn't show anything on the internal screen, even with the original vBIOS in place & OS X loaded (with or without WebDrivers), correct? I could be mixing stuff up, it's quite some time ago...

If this is the case, I don't think it can be changed with a VBIOS mod, it's looking more like a hardware issue (i.e. wrong physical signal type connected to your integrated display).

Despite that, our EFI experiments didn't work (the EFI binary didn't load), which might have been a stupid mistake. The MXM VBIOS was looking very different compared to the PC ROM, so integrating the EFI might need a little more work.
 

magdale

macrumors newbie
Feb 26, 2016
8
1
Italy
Hi there! I read the thread and I saw, maybe if I understand correctly, it is not possible to upgrade the video card or if you can, it is not 100% compatible.

I have an iMac 27 "mid 2011 A1312 problems with the video card HD 6970M 2GB. I'm out of Apple's program to replace it. At this point I would like to try the reball the BGA chip. At the same time I would like to replace the chip but do not know what and where to take it.

I saw this (http://it.aliexpress.com/item/100-t...ip-reball-with-balls-Chipset/32566086895.html) but I am not sure it is correct. Can someone help me?
 

VicLev

macrumors member
Jun 6, 2013
37
3
No, the lack of boot screen is due 100% to not having Mac EFI on the cards.

I have been offering for quite some time to work with someone to create a better iMac GPU card, I am 90% certain I could write an EFI that would at least enable boot screen, and possibly brightness control as well. I know how, I know the roms and the display mapping. What I don't have is an iMac or the space and time to take apart, etc. My prior posts in this thread spell it all out.

Any Nvidia card that has been shown to work in OSX is a good candidate. Some people here have done some of the hard work already.

Florian is a clever guy, but hasn't spent as much time immersed in Mac EFI.

what do you need for that? i am willing to provide the hardware, though i am on the other side of the planet!
[doublepost=1456835347][/doublepost]
If I recall correctly, your GTX 780 didn't show anything on the internal screen, even with the original vBIOS in place & OS X loaded (with or without WebDrivers), correct? I could be mixing stuff up, it's quite some time ago...

If this is the case, I don't think it can be changed with a VBIOS mod, it's looking more like a hardware issue (i.e. wrong physical signal type connected to your integrated display).

Despite that, our EFI experiments didn't work (the EFI binary didn't load), which might have been a stupid mistake. The MXM VBIOS was looking very different compared to the PC ROM, so integrating the EFI might need a little more work.


no, it did work, though no bootscreen and no brightness control. i am ok with no boot screen, but lack of brightness control is killing me.
 
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yifuhood

macrumors member
Nov 3, 2014
75
16
what do you need for that? i am willing to provide the hardware, though i am on the other side of the planet!
[doublepost=1456835347][/doublepost]


no, it did work, though no bootscreen and no brightness control. i am ok with no boot screen, but lack of brightness control is killing me.

I will donate some euro for the work, yes I will ! Please guys make it happen. Once for all
[doublepost=1456837935][/doublepost]
No, the lack of boot screen is due 100% to not having Mac EFI on the cards.

I have been offering for quite some time to work with someone to create a better iMac GPU card, I am 90% certain I could write an EFI that would at least enable boot screen, and possibly brightness control as well. I know how, I know the roms and the display mapping. What I don't have is an iMac or the space and time to take apart, etc. My prior posts in this thread spell it all out.

Any Nvidia card that has been shown to work in OSX is a good candidate. Some people here have done some of the hard work already.

Florian is a clever guy, but hasn't spent as much time immersed in Mac EFI.
I know nothing about graphics card , but if you can write the EFI for iMac graphic card upgrade, I will donate for your work.
 
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Fooze

macrumors member
Mar 1, 2016
41
31
I've read through this entire thread and been lurking here for months. I wish MacVidCards offer had more visibility and a computer shop in LA could help. I'm in North Carolina. I know living on the opposite side of the country wouldn't be very efficient but would it be of any help if I offered to test the EFI on my mid 2011 iMac?

I feel pretty comfortable disassembling and assembling the iMac. I upgraded the CPU to the i7, installed a SSD, and cut/mounted an eSATA port into the bottom of the case. I'd love to give the GPU some much needed love but the lack of boot screen and loss of brightness control would bother me.

I'm willing to purchase a used 780M (or any video card deemed appropriate) for MacVidCards to attempt his EFI voodoo on it. I'm mostly a hardware guy, but if you tell me what you need me to do with the code I'm sure I could figure it out. The other option is we could snail mail the card back and forth if that's better for you. Let me know if that's helpful or if a donation would help to get the ball rolling.
 
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magdale

macrumors newbie
Feb 26, 2016
8
1
Italy
As you have read in my previous post is a holder of iMac 27 "mid 2011 problems with the video card. I was planning to replace the chip but at this point I would also be willing to change the video card with 780M. Even I, as Fooze, I replaced ssd and made some changes, but in this project I'd not know how to help you. I could still make a donation if I also could help.

** Excuse me for my bad English
 
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yifuhood

macrumors member
Nov 3, 2014
75
16
I have done every possible upgrade to my iMac 2011, but the video card , since I do not know anything about graphics card ; I am a musician I edit sound mostly. I would really like update the graphics card, but the only thing holds me back is the EFI (no brightness control), I think this will leads to over heating. if donation will help MacVidCards I will be glad to do it.
 

havokalien

macrumors 6502a
Apr 27, 2006
649
52
Kelso, Wa
It wont overheat as the display has a temp sensor which controls the fans. When you take the unit apart it is marked. I use a fan control utility so I can see ever temp sensor value but once set at whatever you want its invisible just like the normal apple fan control.
 

sheldontung

macrumors newbie
May 18, 2013
14
7
Hong Kong
Now I've been using 780m for a while. Everything is awesome until I need an extra display for editing work. As I mentioned before, after the upgrade my iMac won't recognize my Apple Thunderbolt display. But the thunderbolt port still works when it connects to something else such as LaCie hard drives. The good news is I have an OWC thunderbolt 2 dock (all five USB 3.0 ports are okay but the thunderbolt port on this dock doesn't work with thunderbolt display neither) which also contains a HDMI port once connected to my amplifier for multichannel audio output. The bad news is after the upgrade EVEN this HDMI port doesn't work anymore. Thus, my last chance is the Mini DisplayPort to HDMI adapter and I really really doubt if it works. So anyone could give me some suggestions?
 
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madeirabhoy

macrumors 68000
Oct 26, 2012
1,671
620
Now I've been using 780m for a while. Everything is awesome until I need an extra display for editing work. As I mentioned before, after the upgrade my iMac won't recognize my Apple Thunderbolt display. But the thunderbolt port still works when it connects to something else such as LaCie hard drives. The good news is I have an OWC thunderbolt 2 dock (all five USB 3.0 ports are okay but the thunderbolt port on this dock doesn't work with thunderbolt display neither) which also contains a HDMI port once connected to my amplifier for multichannel audio output. The bad news is after the upgrade EVEN this HDMI port doesn't work anymore. Thus, my last chance is the Mini DisplayPort to HDMI adapter and I really really doubt if it works. So anyone could give me some suggestions?


good post sheldontung, am i right in thinking you've now been using it for about 4-6 months without problems?

is there different versions of the 780m or will any one do? i see you bought yours from tabao.com but the site is all in is it japanese or korean, i can't tell.

in hesitant about fitting it, do you think its easy for someone who's got experience of fitting hard drives and memory but thats about it. how quickly and easily can you swap them back? is it harder than putting a 6970m 2gig in? the reason i ask is i was thinking about this as being easier but its nearly twice the price for half the power.

in terms of windows gaming, is a 3.1ghz 2011 with this card going to cope as well as similar on paper specced iMac and windows computers.

thanks in advance.
 

bizzle

macrumors 6502a
Jun 29, 2008
941
42
It's not the hardest thing to replace but it's more complicated than a hard drive. You have to pull all of the RAM, disconnect the majority of the cables from the logic board and remove all the screws from the logic board. If you have a short T8 screw driver you can replace the card without actually having to fully remove the logic board. I've always done it that way (I work on these machines for a living) and it saves some time.
 

yifuhood

macrumors member
Nov 3, 2014
75
16
is the fan running very loud? I just changed my 2011 iMac HDD fan to a 2010 iMac AVC HDD fan for less fan speed(before HDD fan speed 1260, now under 1100. ). now i get 2 - 4 °C hotter on my SSDs, but quieter.

but still I think 780m out put much more heat than the AMD 6970m. so 780m need a bigger heatsink than the current one in the iMac 2011.
do you think this kind of HeatS will help?
http://www.ebay.de/itm/271987340064?_trksid=p2060353.m1438.l2649&ssPageName=STRK:MEBIDX:IT

http://www.ebay.de/itm/111217889517?_trksid=p2060353.m1438.l2649&ssPageName=STRK:MEBIDX:IT

if i put them on the back side of the iMac heatsink?
 
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madeirabhoy

macrumors 68000
Oct 26, 2012
1,671
620
It's not the hardest thing to replace but it's more complicated than a hard drive. You have to pull all of the RAM, disconnect the majority of the cables from the logic board and remove all the screws from the logic board. If you have a short T8 screw driver you can replace the card without actually having to fully remove the logic board. I've always done it that way (I work on these machines for a living) and it saves some time.

any real chance of doing damage if you are careful?
 

Schprecher

macrumors regular
Dec 11, 2015
130
19
Sorry for my English.

Before know the problem with 780m in iMac 27 2009-2011, we need to think about of newer iMac's with GTX 780M 4Gb.
The Question is, why GPU-Z can't read Vbios from iMac's 2013 year.
I think, Main ROM 2013 iMac's create some hidden area in Main EFI space to emulate vbios for Windows,
its first at primary problem to know, where we need to start a thinking to do right efi for mid 2011 iMac's.

Same GPU chip uses on board in newer iMacs 2013, and same GDDR5 soldered on board near GPU,
to first steps, we need fully dumped Main EFI - iMac 27 a1419 late 2013, i7, gtx 780m 4gb.

And other what i say to this, is
Why a older true iMac's card from 2009-2010 like 4850m, 5750m can't working in iMac mid 2011.
this second Question to think, is problem may be in Main EFI iMac mid 2011?

Why iMac's 2009-2010 can know 6970M cards?
Why iMac's 2011 can't working with early true iMac's card 2009-2010 year.

Let efi Guru says to us, FITC - or Flash Image tool for Intel Chipsets can unpacking EFI?
or this things will hided from us for long time, with no chance to see the truth?

Or Just problem in little kext (i called this), efi part on GPU card rom
Driver on inside a driver, little apple trick to change output port? and some little part to change backlight control.

come on, any idea about this?
 

havokalien

macrumors 6502a
Apr 27, 2006
649
52
Kelso, Wa
There is a firmware that tells it its a mac and how to work. All the apple cards will basically work across different years of the imacs and just work. Thats because they have correct firmware for the hardware. The OS has drivers built in for all the cards. The reason some PC cards work but lose function is the driver is in the OS but you lose brightness control and boot apple since the firmware is not there to load like in the apple version. Apples firmware chip is larger. If you search the internet some you can get more specific answers. This topic is years old for the imacs.
 
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