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

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nekton1 said:
Thank you—that's logical BUT this morning it is back to booting to list of boot disks (attachment) View attachment 902972
after about 6 seconds and to Finder after another 6 seconds after selecting boot disk.
I have done NOTHING between shutting down last night (when reboots were taking as long as 60 seconds from RAM post to appearance of boot disk icons) and restarting this morning.
I've no rational explanation.
The ONLY difference between last night and this morning is temperature. Last night after runing all day, the iMac was hot (HW Monitor on the Catalina Loader showed temps of 45° to 50°C on many dies and 70°C on the GPU die—have to do something about that with some heatsink adjustments). After 12 hours off, everything is in the 30°C range; could this be causing the different times in appearance of above screen?
Click to expand...
Open Core loads a modified version of FakeSMC that allows you to see your GPU die temps. If' it's sitting that high on idle that could be why some boots you have no display at all. Yes like you said I'd check my heatsink and paste to make sure there is sufficient coverage. Also keep your Optical drive fan at least 2500rpm.

I'm not sure what you are using on VRAM chips but k5 Pro is the recommended paste as it's basically what Apple used. Thermal pads are advised against. Not saying you did, but I like to repeat this fact for other newcomers reading this thread.
 
highvoltage12v said:
Open Core loads a modified version of FakeSMC that allows you to see your GPU die temps. If' it's sitting that high on idle that could be why some boots you have no display at all. Yes like you said I'd check my heatsink and paste to make sure there is sufficient coverage. Also keep your Optical drive fan at least 2500rpm.

I'm not sure what you are using on VRAM chips but k5 Pro is the recommended paste as it's basically what Apple used. Thermal pads are advised against. Not saying you did, but I like to repeat this fact for other newcomers reading this thread.
Click to expand...

Arctic MX-4
 
I don't know WTF Apple thermal design engineers were thinking (they weren't) when they designed the GPU cooling for the 2009 to 2011 27" iMac series, but why they located the ODD drive between the fan and the GPU heat sink was a design mistake of EPIC proportions, explaining why droves of these 27" iMacs see heat-related GPU failures.
First, the GPU needs much more cooling than the ODD, and second, when the ODD is occasionally in use, the drive-generated heat actually heats the GPU heat sink!
I recently replaced the ODD in mine with an SSD using an OWC ODD to SSD conversion kit and the dead HD4850 with a K1100M flashed with Nick's rom.
Yesterday, when troubleshooting some Catalina Loader random boot time issues, HW monitor was showing the GPU die at 80°C in the red at rest with an ODD fan rpm of 2500. So, today I decided to take some countermeasures. I had used Arctic MX-4 on the nVidia GPU so that was OK, but the VRAM chips on the non-heat sink side of the K1100M card were uncooled so I applied some copper cooling fins and plates to them.
Next, to increase the air flow by minimizing leaks from the fan output to the heat sink, I cut a thin polycarbonate sheet to cover all the leak paths and secured it in place with Kaptan tape.
Now, the GPU die is showing 65°C after 1 hour of playing Captain America streamed from Plex with the ODD fan at 2150 rpm; that's a 15°C drop under load for 350 rpm less.
Whoever designed the thermals for this iMac series should have been taken to task (fired) and Apple should have had a product recall to fix this.
 
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nekton1 said:
I don't know WTF Apple thermal design engineers were thinking (they weren't) when they designed the GPU cooling for the 2009 to 2011 27" iMac series, but why they located the ODD drive between the fan and the GPU heat sink was a design mistake of EPIC proportions, explaining why droves of these 27" iMacs see heat-related GPU failures.
First, the GPU needs much more cooling than the ODD, and second, when the ODD is occasionally in use, the drive-generated heat actually heats the GPU heat sink!
I recently replaced the ODD in mine with an SSD using an OWC ODD to SSD conversion kit and the dead HD4850 with a K1100M flashed with Nick's rom.
Yesterday, when troubleshooting some Catalina Loader random boot time issues, HW monitor was showing the GPU die at 80°C in the red at rest with an ODD fan rpm of 2500. So, today I decided to take some countermeasures. I had used Arctic MX-4 on the nVidia GPU so that was OK, but the VRAM chips on the non-heat sink side of the K1100M card were uncooled so I applied some copper cooling fins and plates to them.
Next, to increase the air flow by minimizing leaks from the fan output to the heat sink, I cut a thin polycarbonate sheet to cover all the leak paths and secured it in place with Kaptan tape.
Now, the GPU die is showing 65°C after 1 hour of playing Captain America streamed from Plex with the ODD fan at 2150 rpm; that's a 15°C drop under load for 350 rpm less.
Whoever designed the thermals for this iMac series should have been taken to task (fired) and Apple should have had a product recall to fix this.
Click to expand...
It's realy a bad desig in regard to the GPU, I might remove the optical drive and maybe add a FAN or some in that place, when i add my new card.

i think more of desaster is the cooling at the CPU. the CPU is cooled prefect. Direct air flow at the heatsink all cooled perf.... wait.. what is above the CPU ??????
ohh yes, the PCB for the Power(PSU). fryed PSU for lunch ?.. Lol
 
Been playing around installing Catalina 10.15.4 over 10.14.3, and after a couple of days had success on a 2011 27”with a GTX765M and 21” with a K2000M, using dosdude 1’s 1.4 patcher app. Found that after first boot the display go’s black, but if you just let it run for 30 mins or so then restart and boot back into the patcher and install Post-Install Patches but plus the APFS Patch, it installed with no black display. Only problem was no WiFi but ran OnyX Maintenance and WiFI came back. Hope this help’s someone.

 
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Lodge52 said:
Been playing around installing Catalina 10.15.4 over 10.14.3, and after a couple of days had success on a 2011 27”with a GTX765M and 21” with a K2000M, using dosdude 1’s 1.4 patcher app. Found that after first boot the display go’s black, but if you just let it run for 30 mins or so then restart and boot back into the patcher and install Post-Install Patches but plus the APFS Patch, it installed with no black display. Only problem was no WiFi but ran OnyX Maintenance and WiFI came back. Hope this help’s someone.
Click to expand...

Congrats on getting it working - there's hope :)
Upgraded my 2011 27" with GTX765M, using DosDude1 1.4 patcher and fresh 10.15.4 install. It isn't detecting the internal display - external is working fine. It was working fine before with 10.15.3.

It feels like it's missing a kext file for the internal display... Any ideas?
 
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Jforte said:
Let me tell you my experience with a second hand imac 27 mid 2011:

I bought this machine regarding some important points that i've found here:
1. A 27 mid 2011 one (not 2010, not 2009) cheap;
2. With the i7 2600 CPU (no need to upgrade it);
3. With a 6970 (mxm-b) card working (this card comes with the bigest and the best gpu heatsink;
4. with a ssd kingston a400 480gb.

I bought a nvidia mxm-b 780m card. Be carefull taking off the x-bracket, use a hair dryer to "unglue" it.
Used a drill to mod the heatskink (i also bought a second one) and the x-bracket to open holes for the screws. Don't use the x-bracket from 6970m (it is to big).
The card didn't work at all, it was from a clevo, but i bought a ch341a programmer with the clip, install drivers and software on a windows pc, flash the bios (kepler beta 3 for 780m). After this the card worked has expected. Sometimes someone will buy a card that doesn't boot, but the vbios is the important key here. Flash it first!
Until someone create another modded vbios, i don't have auto brightness, but i use brightness slider app (the #1 post it is very important ot read, remember).
I also upgrade RAM, with 4 pc3l 12800 (1.35v) crucial 8GB each (32gb total).
I also bought a second ssd (another kingston a400 480gb) a caddy for dual ssd on the hdd space, a cable to connect the second ssd (remember, imac 27 mid 2011 has 3 sata ports, Sata 0 and Sata 1 (6gbps) and sata 2 (3gbps for the superdrive). installed macos catalina (use dosdude1 pach) and now i have a raid 0 system (double sdd speed) with 960GB.
I teardown ALL to clean, to put termal paste on CPU, and thermal paste and thermal pads on GPU.

I now have this spare parts (1 3 copper pipe GPU heatsking; 1 mxm-b 6970m card 1GB GDDR5; 1 nvidia 675mx card 4GB GDDR5 (also metal support and with boot image); 2X 2GB RAM pc3 10600 DDR3.
I'm from Portugal, if someone want some of this parts (i'm selling those) or if someone needs some help from a newbie, pm me. I'm on social isolation with my family, nothing much to do...

Great machine!
Click to expand...
I might be interested in the GPU's you've got and also, what state is your spare heatsink in? Did you grind it down/could you? I'm very apprehensive about modifying my heat sink without having a spare on hand.
 
If you are missing internal display, it is because of the VBIOS on your cards. You MUST flash custom VBIOS linked in post #1 for guaranteed internal display support. Previously, some default Dell VBIOS had internal display support out of the box, but there is no reason to mess with these if you are using a card with custom Nick VBIOS.
 
Thanks @NOTNlCE - It's worth a go to rule it out. I'll order some bits as I don't have enough for the vbios upgrades yet. Might take a while with delivery and spare time to take it apart again :)
Just seems odd that the gpu and external display appears to be detected fine.
Screenshot 2020-04-02 at 14.07.09.png
 
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mattchr said:
Thanks @NOTNlCE - It's worth a go to rule it out. I'll order some bits as I don't have enough for the vbios upgrades yet. Might take a while with delivery and spare time to take it apart again :)
Just seems odd that the gpu and external display appears to be detected fine.
View attachment 903054
Click to expand...

Yes - looks like you have stock VBIOS on your card. The reasoning here is because the display output port mapping is embedded in the VBIOS itself, rather than in software via kernel extension. Conversely, AMD cards are the opposite. They use a "Framebuffer" that can be patched in software to output signals that we want. The NVIDIA VBIOS that work require there to be an embedded DisplayPort signal in the port mapping in order to communicate with the iMac display. Most have a standard DisplayPort signal by default, which is why your external display works fine. If you flash Nick's VBIOS onto your 765M when you get a chance your internal display will come to life.

EDIT: Sorry if I am rambling - I tend to want to understand *why* something does not work and how to fix it rather than just blindly following direction.
 
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Hi!

How can I buy a P&P vbios upgrade for my iMac ? I have a GTX770m in computer but I have not boot screen.
Thanks!
 
Hi!
I did it but I have black screen in safety mode as well. :) I can't fallowing instructions because I can see nothing.
We tried an external screen as well but same black. We can see nothing.
 
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mattchr said:
Thanks @NOTNlCE - It's worth a go to rule it out. I'll order some bits as I don't have enough for the vbios upgrades yet. Might take a while with delivery and spare time to take it apart again :)
Just seems odd that the gpu and external display appears to be detected fine.
View attachment 903058
Click to expand...
z33capt13n said:
I might be interested in the GPU's you've got and also, what state is your spare heatsink in? Did you grind it down/could you? I'm very apprehensive about modifying my heat sink without having a spare on hand.
Click to expand...
The heatskink is on good condition, stock (not modded). I also have a 2 pipe large heatskink, excelente condition, not modded.
 
Hi Guys!

This is my mac. I have not boot screen unfortunately. And my keyboard keys are't work. Which way easier for setup the vbios for GTX 770m? Thanks for everyone!
 

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Tontal73 said:
Hi!
I did it but I have black screen in safety mode as well. :) I can't fallowing instructions because I can see nothing.
We tried an external screen as well but same black. We can see nothing.
Click to expand...
Use the usb stick method !!!! if you can connect to the imac (owning the the GTX770) with another another imac in the same wired network, you can flash the card even if you are a black screen !
--> created a pre-made USB that can flash the iMac
 
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ZenSurfeur said:
Use the usb stick method !!!! if you can connect to the imac (owning the the GTX770) with another another imac in the same wired network, you can flash the card even if you are a black screen !
--> created a pre-made USB that can flash the iMac
Click to expand...
This is a good method. Remind. If you'll use the pen a second time, please do all steps again, even formar the pen. If you use a first time to rest, and that again to flash the card, you'll have problems to acess the iMac again.

The ch341a mini programmer is a good method too, i used this method.
 
Jforte said:
This is a good method. Remind. If you'll use the pen a second time, please do all steps again, even formar the pen. If you use a first time to rest, and that again to flash the card, you'll have problems to acess the iMac again.

The ch341a mini programmer is a good method too, i used this method.
Click to expand...
with the usb stick, nvflash didn't find my card k2100m (black screen - led diagnostic 2/4), I am waiting for a ch341a usb flasher... last chance :) even if I think the card is dead but who knows
 
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@jowaju i managed to install your Window's. but pleas.. 😊 make it to WIN 10, to increase the compatible computers.
i trying it on my macbook. and i get a blue screen of dead
 
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