iM 4,1-14,4 2011 iMac Graphics Card Upgrade

[OnawaAfrica]

Just came across this thread and don’t feel like reading 14,000 posts... I recently acquired a 2011 21.5” iMac that is efi locked. Does anybody here have the capability to unlock it? I can still use it if I put in a drive with an operating system already on it but I just got it to resell it and would like to sell it unlocked.

u can unlock it with a SPI flasher or a raspberry pi. u have to dump the efi from the SPI Chip and Edit the Dump and re flash the SPI Chip. pls research about flashing Mac EFI with Raspberry pi / SPI Flasher

 

[herrdude]

u can unlock it with a SPI flasher or a raspberry pi. u have to dump the efi from the SPI Chip and Edit the Dump and re flash the SPI Chip. pls research about flashing Mac EFI with Raspberry pi / SPI Flasher

I don't think we should encourage this type of behaviour. Mods will shut down a thread pretty quickly that talks about bypassing Apple security measures.

 

[TimothyL]

u can unlock it with a SPI flasher or a raspberry pi. u have to dump the efi from the SPI Chip and Edit the Dump and re flash the SPI Chip. pls research about flashing Mac EFI with Raspberry pi / SPI Flasher

Thanks! Sorry for crashing your thread with an unrelated question...

 

[B0URNE]

Reading your latest post you experience the throttling in the middle of a medium load situation. I would think the SMC is working half way the avoiding over load of over heating. Since I am not the BIOS developer my understanding of the cooperation between kext (driver), SMC (system management controller) and vBIOS is limited to observation, never did any reverse engineering on that.

Using a 70W card with the 21.5 models has it‘s limits, @highvoltage12v wrote about this on the first post. I do not know the situation in your country regarding the used system pricing. Here it is definitively better to jump on a cheap GPU dead 27 inch system and use the MXM-B cards in such a models. The repair costs are the same (GPU, memory, SSD) and you get a nice shiny bright 27 inch display.

I've done a little more research based on your heating hypothesis and found some information below that may shed some further light.

BD PROC HOT is causing my GPU to throttle down and get stuck

I have noticed that my GTX 770M will sometimes downclock itself, according to gpu-z, for "power" reasons. This makes no sense. The card has more than enough power as its a laptop. Restarting windows fixes it, so i have a feeling its due to the driver being retarded. This seems to happen when...

www.techpowerup.com

I'm thinking now this maybe due to the CPU incorrectly throttling itself due to "BD PROC HOT"? The processor thinks it is overheating @ 80C and consequently throttles the GPU.

I wonder can the 770M GPU throttling be stopped by turning off "BD PROC HOT".

Obviously there is the 27" option but where the total hardware TDP is less than the PSU 205W supply it is curious and should work.

 

[Ausdauersportler]

The TDP you are estimated is on average, unfortunately the peak values can be very different, even on normal/med load. So you can do your hypthetical estimations all day long, the reality is a different one.

You can change back the GPU or modify the BIOS to lower average and so lower peak values (what would be the same as changing the GPU).

Honestly I am not interested in supporting or discussing a meta stable solution driving potential new users into problems all day long. You can follow and continue your little experiment, but I do not understand why you are ignoring what other have already tried and failed doing this - we put the on the first post on purpose.

 

[B0URNE]

It looks like the video memory is over-heating, try turning your ODD fan up.

If that doesn't fix it try flashing this patched bios with lower memory clocks,

it will also enable brightness control on 765M & 770M with the OpenCore loader!

This hybrid 780M bios doesn't need OpenCore, it just fixes the Boot Camp problem.

Enjoy!

Hi @Santa's Little Helper,

I gather this is an improvement on the Nick[D]vB vbios? Does in go further and underclock the GPU? I am wondering whether this may resolve my current problem with the 770M throttling in my 21.5" Mac under med-high render loads.

Thanks

 

[B0URNE]

The TDP you are estimated is on average, unfortunately the peak values can be very different, even on normal/med load. So you can do your hypthetical estimations all day long, the reality is a different one.

You can change back the GPU or modify the BIOS to lower average and so lower peak values (what would be the same as changing the GPU).

Honestly I am not interested in supporting or discussing a meta stable solution driving potential new users into problems all day long. You can follow and continue your little experiment, but I do not understand why you are ignoring what other have already tried and failed doing this - we put the on the first post on purpose.

Thanks for the TDP/BIOS headsup.

Frankly, I'm not ignoring the obvious by way of the 27" option as it is purely an exercise trying to push the engineering and capability of the 21.5" model. Also I'm certainly not intending to drive people towards this path but to open discussion as it has a place and deserves some extra loving. After all isn't this point the point of any experimental engineering project trying to test boundaries of what is possible and chart new solutions?

I don't necessarily believe that it's a failed project simple because others have not made it work. Quite the contrary it's just another way that doesn't work until something that does.

BTW My Ultra45 still happily kicking away and being very productive

 

[Ausdauersportler]

Thanks for the TDP/BIOS headsup.

Frankly, I'm not ignoring the obvious by way of the 27" option as it is purely an exercise trying to push the engineering and capability of the 21.5" model. Also I'm certainly not intending to drive people towards this path but to open discussion as it has a place and deserves some extra loving. After all isn't this point the point of any experimental engineering project trying to test boundaries of what is possible and chart new solutions?

I don't necessary believe it's a failed project simple because others have not made it work. Quite the contrary it's just another way that won't work until something that does.

BTW My Ultra45 still happily kicking away

No, there is a difference between exploring or engineering on one side and ignoring simple physical facts on the other. You can read back the thread, we had more than a dozen of such attempts. Some tried to implant the bigger 310W power supply (does not fit physically), some wanted to use an external one (where is the gain in that?). At the end the day you have to accept the physical reality (we call these reality natural laws which cannot in contrast to those made by a legislative be reshaped, ignored, negotiated, bent to a level where you cannot recognise them, again).

This is a nice talk, not more. My Ultra 80 has been retired because it ate up the complete (power) budget. When I need a taste of Solaris I fire up a virtual machine these days.

 

[passatgt]

Hi @highvoltage12v

I have been slowly following this forum and upgrading my iMac2011 21.5" with parts for uni study/play and it has been quite a fun and rewarding exercise. Now I've reached a wall dealing with a graphics card problem.

My system setup is as follows:
View attachment 1769493View attachment 1769489

System imac 21.5" mid 2011 (PSU 205W)
CPU: i7-2600s (upgrade)
GPU: Dell GeForce GTX 770M Nick[D]vB vbios
Mem: 16GB
SSD: 500GB EVO
DVR: None
OS: Win10H2

For all intensive purposes the 770M with this combo works fine for regular productivity work but it stops there with gaming. I'm experiencing issues where under medium-heavy gaming load the GPU clock cycles from max/min value of 850MHz/300MHz from a starting temp 48C to finally a stable ~70C. According to the GPUShark it states under Limiting policies (NVIDIA) "GPU power limit reach". You can see the throttling on the snapshot above.

How can this be the case as I thought the total TDP with all these above upgrades was less than the 205W afforded by the PSU? If this is a GPU architecture specific _driver_ feature can I change the power limiting policy? I am really puzzled as the 765M with identical TDP (75W) has been shown to work well in the 21.5.

Any help would be greatly appreciative from you and the community.

Whats that red board with the sata connectors?

For the GPU memory modules, K5 pro is the recommended option, not thermal pads, i think you can gain a few degrees there. You could redirect some airflow from the HDD fan towards the GPU, since the SSD does not need active cooling, like the old large HDD. You mentioned you removed the ODD to leave space for the SSD: in the original configuration if you need a second SSD, they put it under the ODD. But since you have an SSD in the main bay already, you can simply mount the second one on the top of each-other, it fits easily, still smaller than a 3,5" drive. So i would put back the ODD to improve airflow. Did you tried running benchmarks with lowering the brightness to minimum, maybe removing the second SSD, turning off WiFi, Bluetooth? (just to save a few watts...). I think that power supply is the bottleneck. Maybe try it with the old CPU, which has a lower TDP(45W vs 65W) and see if you still have the same issue? If not, it's going to be the power supply.

 

[internetzel]

Thanks for the TDP/BIOS headsup.

Frankly, I'm not ignoring the obvious by way of the 27" option as it is purely an exercise trying to push the engineering and capability of the 21.5" model. Also I'm certainly not intending to drive people towards this path but to open discussion as it has a place and deserves some extra loving. After all isn't this point the point of any experimental engineering project trying to test boundaries of what is possible and chart new solutions?

I don't necessarily believe that it's a failed project simple because others have not made it work. Quite the contrary it's just another way that doesn't work until something that does.

BTW My Ultra45 still happily kicking away and being very productive

You also have to consider that the maximum current that can be drawn by the GPU is also limited by the actual conductor cross section on the PCB. The 21.5" logic boards would have MXM power conductors of smaller cross section if tailored to the system's specifications.
There would be no way around this other than soldering additional wires in parallel.

 

[B0URNE]

Whats that red board with the sata connectors?

For the GPU memory modules, K5 pro is the recommended option, not thermal pads, i think you can gain a few degrees there. You could redirect some airflow from the HDD fan towards the GPU, since the SSD does not need active cooling, like the old large HDD. You mentioned you removed the ODD to leave space for the SSD: in the original configuration if you need a second SSD, they put it under the ODD. But since you have an SSD in the main bay already, you can simply mount the second one on the top of each-other, it fits easily, still smaller than a 3,5" drive. So i would put back the ODD to improve airflow. Did you tried running benchmarks with lowering the brightness to minimum, maybe removing the second SSD, turning off WiFi, Bluetooth? (just to save a few watts...). I think that power supply is the bottleneck. Maybe try it with the old CPU, which has a lower TDP(45W vs 65W) and see if you still have the same issue? If not, it's going to be the power supply.

Thanks for the reply. I have the K5-pro paste but opted for the artic pads as the transfer medium for the VRAM so I may try that option to see if it makes a difference. As mentioned earlier, I didn't end up adding the second SSD (due power consumption concerns) but I can return the ODD bracket see if there is any noticeable improvement.

The CPU could the next test. I feel though that it is possibly a power consumption issue as technically PC PSUs are usually 80% efficient so I doubt iMac would be much of an improvement.

 

[B0URNE]

You also have to consider that the maximum current that can be drawn by the GPU is also limited by the actual conductor cross section on the PCB. The 21.5" logic boards would have MXM power conductors of smaller cross section if tailored to the system's specifications.
There would be no way around this other than soldering additional wires in parallel.

I actually considered that the Vs conductor tracks in this model's logic board could be the limiting factor. However from experience most well designed power electronics down at the PCB level accomodate for greater power draw than what was originally intended, or supplied. It essentially mitigates circumstances where power requirements need to be upgraded should it ever happened.

 

[dksp]

Good point there. Do you have brightness control enabled?

With my K2100M and no brightness control (before installing open core solution) the overall temperature of the iMac was about 10C° more.

 

[m0bil]

Quoting myself to highlight the conclusion of the throttling.

Pulled the logic board out and removed CPU fan, detached Amp temp sensor, it had a slightly wet feeling, the insulated cables are slowly deteriorating and rubbing them resulted with black gunk on fingers and a hair like slither of plastic. On one of my 21.5 2011's I have had this fan cables insulation totally deteriorate and causing a major shorty blowing several components on the LB so upgraders beware, if you are disassembling check all the wiring for corrosion.

Happy to report wiping down the cables and jiggling them + temporarily placing the sensor near the HDD fan and the issues are gone.

So happy it is not logic board or PSU related, saved a bunch of money.

Let this be a lesson to upgraders, s##t can happen during a upgrade that is totally unrelated to the upgrade and completely throw the diagnostics off. Cover all your bases first and check everything before resorting to the iMac GPU thread helpline.

Happy days here, smoking fast iMac again, yeaaaahaooow!!!
View attachment 1769517View attachment 1769518

View attachment 1769521View attachment 1769523

Great work on fixing this issue! I see now your Valley benchmark is around 10% above the one I scored with identical hardware. Which K3100M rom were you using ? I think mine was K3100M_V3.rom

 

[The_Croupier]

Great work on fixing this issue! I see now your Valley benchmark is around 10% above the one I scored with identical hardware. Which K3100M rom were you using ? I think mine was K3100M_V3.rom

K3100_BFR worked for me 😉
Thanks, over the past 3 months I have learnt so much about troubleshooting these iMacs, I'm stubborn and dont give up until there is fire and smoke coming out of these macs 😆

Really I'm a amateur but dont mind having a go at soldering and basic repair.

Pretty stoked today, made a risky move and bought a faulty 780m GPU on eBay.

The seller didn't disclose what the faults were, just said its not booting.

Stupidity I bought it for $70 AUD inc postage.

So I chuck it in without flashing and Mac shuts down around the time the GPU should kick in so no post.

I load up GRML and the card is detected 🙏
Flashed it to @nikey22 780_BR3 on reboot classic GPU failure blue horizontal razor lines all over screen, bummer.
Nothing to loose now so blasted it at 480c for 8 min on diode and vrams with my elcheapo AliExpress heat gun, reinstalled and presto 😀

It will be interested to see how long it lasts 🙄

 

[FlorisVN]

K3100_BFR worked for me 😉
Thanks, over the past 3 months I have learnt so much about troubleshooting these iMacs, I'm stubborn and dont give up until there is fire and smoke coming out of these macs 😆

Really I'm a amateur but dont mind having a go at soldering and basic repair.

Pretty stoked today, made a risky move and bought a faulty 780m GPU on eBay.
View attachment 1770088
The seller didn't disclose what the faults were, just said its not booting.

Stupidity I bought it for $70 AUD inc postage.

So I chuck it in without flashing and Mac shuts down around the time the GPU should kick in so no post.

I load up GRML and the card is detected 🙏
Flashed it to @nikey22 780_BR3 on reboot classic GPU failure blue horizontal razor lines all over screen, bummer.
Nothing to loose now so blasted it at 480c for 8 min on diode and vrams with my elcheapo AliExpress heat gun, reinstalled and presto 😀
View attachment 1770098
It will be interested to see how long it lasts 🙄

good, but I would still recommend you have bought a known good working GTX780m.
I hope it lasts for a while, but I doubt it.

Keep hunting for a new MXM card, GTX680m also just got a vbios..

 

[hflopez]

Just press alt/option on boot or fire up the internal display, read the first post again and search for black screen, install OCLP or the patched AGC as described there.

Thanks for reply
This model was supposed to work without having to install OCPL
Moreover, i am not able to do or install anything cause just plays startup sounds several times having just the light of the screen on but in black.

Regards

 

[The_Croupier]

good, but I would still recommend you have bought a known good working GTX780m.
I hope it lasts for a while, but I doubt it.

Keep hunting for a new MXM card, GTX680m also just got a vbios..

I totally agree, and I also do not recommend anyone shelling out that kind of money on a gamble.

I think I've just gone a little bit mad after fixing up these old macs 🤪

 

[The_Croupier]

Thanks for reply
This model was supposed to work without having to install OCPL
Moreover, i am not able to do or install anything cause just plays startup sounds several times having just the light of the screen on but in black.

Regards

There is no guarantees here that a card that works for some will work for all, even on exact same hardware.

The 880m is problematic, read my posts on trouble shooting my son's recent 880m (Samsung) install.

Also did you check for image on external display?

Did you install correctly and modified the heatsink? If not perhaps your shorting the board.

You have to read this entire thread or at the very least heavily search this thread.
Then try all the fixes others have tried.

Lastly after trying everything you need to, in detail, explain the troubleshoiting you have tried, and then ask for advice.

Ok?

 

[OnawaAfrica]

Thanks! Sorry for crashing your thread with an unrelated question...

welcome. well that's not my thread tho

 

[OnawaAfrica]

I don't think we should encourage this type of behaviour. Mods will shut down a thread pretty quickly that talks about bypassing Apple security measures.

true u right. sorry for discussing such here

 

[hflopez]

There is no guarantees here that a card that works for some will work for all, even on exact same hardware.

The 880m is problematic, read my posts on trouble shooting my son's recent 880m (Samsung) install.

Also did you check for image on external display?

Did you install correctly and modified the heatsink? If not perhaps your shorting the board.

You have to read this entire thread or at the very least heavily search this thread.
Then try all the fixes others have tried.

Lastly after trying everything you need to, in detail, explain the troubleshoiting you have tried, and then ask for advice.

Ok?

Yes i read your comments about that, but did not get any clue, id just started working after being turned on for a while?

the heatsink you mean the back X to place it? I use the original 6970M, seems to be ok without modifications, maybe I am wrong, will post a pic when i dissasembly the GPU again.

About checking with an external display, i am not sure how to do it, because i tried to connect the imac to the tv, but when i start i do not get anything on the TV.
The iMac just stays like this:

I also checked the main board, and it has the 4 leds on when it´s running
thanks in advance.

Regards

 

[motorm3]

Hi can someone help i had a perfectly running Windows 10 on IMac mid 2011 in legacy mode but now I try to install the OCLP I've done it step by step and it won't install i get blue screen upon install and crashes and the patrician I do in exfat guid partition map but windows won't let me install. Is there any way to install Windows easy way on IMac mid 2011.

 

[passatgt]

Hi can someone help i had a perfectly running Windows 10 on IMac mid 2011 in legacy mode but now I try to install the OCLP I've done it step by step and it won't install i get blue screen upon install and crashes and the patrician I do in exfat guid partition map but windows won't let me install. Is there any way to install Windows easy way on IMac mid 2011.

Delete both partition in the installer(Drive 1) and select that to install, it should work. If its ExFat, the windows installer can delete it and create an NTFS instead. After restart, you will get a blue screen. Boot back into MacOS, install NTFS for Mac, so you can see your windows files. Go to Windows/System32/Drives folder and look for the igdkmd64.sys file, delete it. (you need the ntfs app i mentioned to delete the file). Now boot back into Windows, finish the install. Go to Device Manager(right click on start menu) and under Displays, disable the igpu device, so it won't try to reinstall the igdkmd64.sys file.

If you can boot into the windows startup thing where you can access the command line or safe mode, you can use that to delete the igdkmd64.sys file too.

 

[motorm3]

Delete both partition in the installer(Drive 1) and select that to install, it should work. If its ExFat, the windows installer can delete it and create an NTFS instead. After restart, you will get a blue screen. Boot back into MacOS, install NTFS for Mac, so you can see your windows files. Go to Windows/System32/Drives folder and look for the igdkmd64.sys file, delete it. (you need the ntfs app i mentioned to delete the file). Now boot back into Windows, finish the install. Go to Device Manager(right click on start menu) and under Displays, disable the igpu device, so it won't try to reinstall the igdkmd64.sys file.

If you can boot into the windows startup thing where you can access the command line or safe mode, you can use that to delete the igdkmd64.sys file too.

Yes on instalation i get blue screen and message that this the fault igdkmd64.sys and the computer restarts and try again but crashes with this fault all the time so it won't let me install Windows 10.i would appreciate if you could help me install Windows. If you could explain to me how to do this step by step and deleting this igdkmd64.sys in safe mode or some how because its very tricky do get it installed. Before Windows was running no problem in legacy mode. Please help thanks.