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iM 4,1-14,4 2011 iMac Graphics Card Upgrade
- Thread starter MichaelDT
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Done, but no clues about how to actually flash the vbios.Check the first post
this post helped me flash the k1100m but it should be similar if you're using a ch341a programmer,
but you will need to use ubuntu or another Linux distro
EDIT: just noticed my typo, and made some changes
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This guide describes flashing with a raspberry pi:
https://www.ifixit.com/Answers/View/296157/What+GPU's+are+compatible+with+iMac+27"+2011#answer420333
Added a few more FAQs to the first post to help with the concerns here and updated VBIOS list to include the newly released Quadro VBIOS.
Hello to all. Please tell me if there are any recommendations when upgrading iMac 27 "2011 to Catalina 10.15.2? And is it worth updating to this OS at all?
Successful flash of the K1100M on my test 2011 27" iMac. Thanks again, @Nick [D]vB for all your hard work.
To anyone who has trouble forcing their iMac to blindly boot Windows, turns out I had a failing SSD in mine and despite me forcing it to boot Win10 over UEFI, it would blue screen on startup (unbeknownst to me, since I had no boot screen at the time.) Unplugged the failing internal SSD and no more issues.
To anyone who has trouble forcing their iMac to blindly boot Windows, turns out I had a failing SSD in mine and despite me forcing it to boot Win10 over UEFI, it would blue screen on startup (unbeknownst to me, since I had no boot screen at the time.) Unplugged the failing internal SSD and no more issues.
Hi,
I got a cheap imac 21" 2011 on eBay. The Display is completly dead. I just want to use it only on my external monitor. Which graphics Card would you buy for using Catalina on that machine?
I got a cheap imac 21" 2011 on eBay. The Display is completly dead. I just want to use it only on my external monitor. Which graphics Card would you buy for using Catalina on that machine?
K1100m or k2000m is your only choice. Preferably k1100m.
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So since i have boot screen, i was thinking about doing a clean install of Catalina + Windows 10. Is there anyone out there that did something like this? I have a primary SSD installed in place of the original HDD and one more SSD in place of the ODD. Ideally Catalina would be on the primary SSD and Windows 10 on the second one. Any ideas how can i do this?
@passatgt I'm curious, why are those his only choices?
The Quadro cards are much slower than the GTX cards. In an Imac 21.5" mid 2011 for example, the MXM-b cards will fit especially if you have an SSD in place. You can even route the HDD fan cooling with a 3D printed piece of curved plastic to direct the airflow over the video card (as long as you have an SSD, which most people do, it will provide enough clearance); also, add some small square heat sinks to the few memory squares that are exposed.
Has anyone had any overheating issues using an MXM-b card in a 21.5" frame???
The Quadro cards are much slower than the GTX cards. In an Imac 21.5" mid 2011 for example, the MXM-b cards will fit especially if you have an SSD in place. You can even route the HDD fan cooling with a 3D printed piece of curved plastic to direct the airflow over the video card (as long as you have an SSD, which most people do, it will provide enough clearance); also, add some small square heat sinks to the few memory squares that are exposed.
Has anyone had any overheating issues using an MXM-b card in a 21.5" frame???
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Its a bit tricky to fit and the heatsink is designed for a smaller card. TDP might be an issue, because for example a k1100m is 45W, while the 765m is 75W. But some people still using it, so it might be fine. But i would go with a mxm-a quadro, it fits better and perfectly fine for a 21". Might be a bit slow for 27"(higher resolution)
Yes, this has been tested here and was not stable, even with custom clocks. The card actually overdrew the power supply, rather than overheating. I would stick with the Quadro cards.
Both should work fine, there are ROMs for each with bootscreen. I preferred the K1100M because performance is almost as good as the K2100M but price is $15 less for me here in the US.
Ah, thanks for that input! So basically... "buy what you can get.."? (depending on opportunities)
EDIT: Any success stories for k2100m's? I've just noticed k1100m's...
Not for the 21,5", going by previous posts... guessing due to heat/tdp?
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See above. It is due to power draw.
EDIT: Here is where user highvoltage12 tested extensively, even with custom clocks, and still found instability. Sure it will work, but I certainly cannot recommend it. I'll link that to the first post to help out future researchers.
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Thank you for the reference @NOTNlCE
This was Oct/2019 when highvoltage12v installed a GTX770m. He had kernel panics for a few reasons. I think he had a bad SSD, he didn't have power mangement kexts for Mojave b/c that OS strips any Sandybridge code, so you have to enter them in manually. He actually had 2 SSDs (maybe 3), could that have contributed to instability? Furthermore, the kernel panics were only happening when he was trying to create a new account, not necessarily with graphic intensive tasks.
@highvoltage12v , can you chime in? Do you still have a 770m in your 21.5" computer, how has it held up for the last few months.
This was Oct/2019 when highvoltage12v installed a GTX770m. He had kernel panics for a few reasons. I think he had a bad SSD, he didn't have power mangement kexts for Mojave b/c that OS strips any Sandybridge code, so you have to enter them in manually. He actually had 2 SSDs (maybe 3), could that have contributed to instability? Furthermore, the kernel panics were only happening when he was trying to create a new account, not necessarily with graphic intensive tasks.
@highvoltage12v , can you chime in? Do you still have a 770m in your 21.5" computer, how has it held up for the last few months.
Hello,
Even with just one new Samsung 850 Evo SSD and original optical drive back in, my iMac would still randomly reboot. It was most apparent in Mac OS Mojave and Catalina. I ended up removing the 770m and installing it into another 27" iMac, the card functions perfectly. My 21.5" iMac now has a k2100m which I feel is a perfect match for the 21.5" iMac, it performs well, no power issues.
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Hi guys, I am the owner of imac 21.5 2011 I ordered a Quadro K2100m. Such a question, will the second screen work after BIOS flashing? And will OS Mojave work well?
Yes and yes. You still need to use the Mojave patcher to install it though. But might as well install Catalina, works just as fine.
Hi guys,
I've got a stock (except memory bumped to 16GB) 21.5" Mid-2011 2.5GHz i5-2400S with AMD Radeon HD 6750M. I'm looking at either the i7-2600S (2.8GHz) or i7-3770S (3.1GHz) for a CPU upgrade (both with 65W TDPs). I'll be replacing the 500GB spinner with a 1TB SSD with OWC cable to deal with loss of internal drive temp sensor/100% fan on issue. For video, it looks like my only option is the Nvidia Quadro K1100M with ROM modified as discussed above to give me a nice stable system that will run the latest macOS. Do I have that right or are there other alternatives I should consider? Thanks in advance for any and all responses.
I've got a stock (except memory bumped to 16GB) 21.5" Mid-2011 2.5GHz i5-2400S with AMD Radeon HD 6750M. I'm looking at either the i7-2600S (2.8GHz) or i7-3770S (3.1GHz) for a CPU upgrade (both with 65W TDPs). I'll be replacing the 500GB spinner with a 1TB SSD with OWC cable to deal with loss of internal drive temp sensor/100% fan on issue. For video, it looks like my only option is the Nvidia Quadro K1100M with ROM modified as discussed above to give me a nice stable system that will run the latest macOS. Do I have that right or are there other alternatives I should consider? Thanks in advance for any and all responses.
Welcome! Any of the cards listed under the 21.5" section on the first post will work, but the K1100M with custom ROM is a great option and seems to be the cheapest from my searchings. In regards to the CPU, you will need to stick with the i7-2600S if you want to upgrade. Despite the socket compatibility, the i7-3770S will not post in a 2011 iMac. Many have tried but none have been successful. Good luck with your upgrades!