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CPU Upgrade iMac Mid 2011

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USB3foriMac

macrumors regular
Apr 15, 2020
165
64
Singapore
I just bought a 2600 i7 for my mid 2011 iMac based on your feedback and image comes up during boot and then goes black once finishes loading, seems like the CPU is taking down the GPU, the computer finishes loading but no image. I have an AMD WX4150 video card Wich I checked that has same TGP value than your K1100m (45W) and I also have one SSD installed, disconnected the DVD an I still get low power, what you'd you think I'm missing? I put back the i5 and everything goes fine so it's definitely the i7 sucking up the power 😅 any help will be appreciated thanks!
Yours is 21.5" so power is a bit tight. However, your setup should work. I had a i7-2600 in a 21.5" myself, no issues.
If you say it works with the i5, I assume you have all necessary patches for your new GPU so that you won't get a black screen? Bootloader/Opencore etc? So you have swapped your i7 back to i5 and no black screen, or did you have the i5 working, then swapped to i7 and it is not working?
If the latter, maybe heat sink not properly applied, chip not mounted correctly, RAM issue, GPU not plugged in correctly...
Maybe try a linux live USB stick, boot from there and see whether it is running?
It could also be something withthe GPU. Check the GPU thread for your specific card.
 

Yasmel Diaz

macrumors newbie
Sep 22, 2020
27
13
Yours is 21.5" so power is a bit tight. However, your setup should work. I had a i7-2600 in a 21.5" myself, no issues.
If you say it works with the i5, I assume you have all necessary patches for your new GPU so that you won't get a black screen? Bootloader/Opencore etc? So you have swapped your i7 back to i5 and no black screen, or did you have the i5 working, then swapped to i7 and it is not working?
If the latter, maybe heat sink not properly applied, chip not mounted correctly, RAM issue, GPU not plugged in correctly...
Maybe try a linux live USB stick, boot from there and see whether it is running?
It could also be something withthe GPU. Check the GPU thread for your specific card.
Yeah, I already have all the patches / openCore and flashed custom bios for the video card and running stable with the i5, then swapped to i7 and screen start flickering a little during boot and then fully dimes to dark, osx finished loading cause I can hear the typing after that, I'll take that it may be a heatsink issue since I notice a really hot air blowing out on the CPU side, will do a try again today, make sure everything is well installed and also put the CPU fan at full speed with FanControl to see how it does, thanks for the time!!
 

USB3foriMac

macrumors regular
Apr 15, 2020
165
64
Singapore
screen start flickering a little during boot and then fully dimes to dark, osx finished loading cause I can hear the typing after
Then it's more likely your backlight connector. Use a torchlight, see whether you can still see something on the screen, logo/icon/clock/cursor or so.
If so, take out the screen and put back. The backlight connector is not the best on iMac.
 

Yasmel Diaz

macrumors newbie
Sep 22, 2020
27
13
Then it's more likely your backlight connector. Use a torchlight, see whether you can still see something on the screen, logo/icon/clock/cursor or so.
If so, take out the screen and put back. The backlight connector is not the best on iMac.
I really appreciate your attention, I'll check that, also I didn't mention it did work the very first time with the i7 then stopped working with the mentioned symptoms ... so yes... It must be a connector issue thanks for lighting me up!
 

StephN999

macrumors regular
Apr 12, 2020
182
110
Cergy, France
Bonjour,

CPU well received (delivery was very fast!!!!) lack of bowl the new clamp I bought is defective, so still waiting...

Have a nice day.
 
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zabumbazarolha

macrumors newbie
Oct 8, 2020
4
5
Before I order anything, can anyone confirm that the Xeon 1275 will work in the 27-inch 2011 iMac? Thanks!
Yes, it works very well, slightly faster than i7-2600 (and costs half the price), but the sleep mode does NOT work, contrary to what has been said about the reason for the sleep issue being the presence or not of the IGPU. The Xeon E3-1275 has exactly the same IGPU as the i7-2600 and still the sleep mode doesn't work.
 

USB3foriMac

macrumors regular
Apr 15, 2020
165
64
Singapore
Based on info from zabumbazarolha, I have updated post 1 to include that there is no evidence that any Xeon with integrated GPU can wake up from sleep. I think it is better to be conservative instead of giving false hope.

If anyone has any results to share on individual Xeons, please update post 1 with the results.

Apart from broken sleep, any other negative impact?
 

Ausdauersportler

macrumors 68000
Nov 25, 2019
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Yes, it works very well, slightly faster than i7-2600 (and costs half the price), but the sleep mode does NOT work, contrary to what has been said about the reason for the sleep issue being the presence or not of the IGPU. The Xeon E3-1275 has exactly the same IGPU as the i7-2600 and still the sleep mode doesn't work.
Unfortunately I have never found a single positive post about the fact that this CPU will not break sleep. Which OS version are you booting/using right now?
 

StephN999

macrumors regular
Apr 12, 2020
182
110
Cergy, France
Bonjour,

I hadn't paid attention to this story with the Xeon + iGPU.

Maybe I'm going to say something stupid, but having Ram ECC would not solve the problem?

In any case it will be part of my future tests, whether the Xeon Ivy Bridge works or not...
 
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Ausdauersportler

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Nov 25, 2019
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Bonjour,

I hadn't paid attention to this story with the Xeon + iGPU.

Maybe I'm going to say something stupid, but having Ram ECC would not solve the problem?

In any case it will be part of my future tests, whether the Xeon Ivy Bridge works or not...
The problem is that some people claim sleep is broken because the iGPU is missing with some XEON CPUs. That claim has never been proven to be correct.

And we should always try to do such experiments on a supported OS first, with is High Sierra (latest).

With all other later systems (Mojave, Catalina, and Big Sur) we have known sleep problems with the iMac 2011 even with the supported stock SandyBrigde CPU. And from my experience some people are not able to install the needed extensions correctly. Which makes it even more complex to get a valid statement.

So please stick for the installation and functionality test with High Sierra!
 
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StephN999

macrumors regular
Apr 12, 2020
182
110
Cergy, France
Re,

That's what I thought, thank you for these precisions! ;)

Have a nice day.

Edit: Logically, if the Ivy Bridge works, there would be no problem with extensions, since these processors are supported in the latest systems, I can't wait to test this as soon as possible, I'm really not happy to have to wait again...
 
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Ausdauersportler

macrumors 68000
Nov 25, 2019
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Re,

That's what I thought, thank you for these precisions! ;)

Have a nice day.

Edit: Logically, if the Ivy Bridge works, there would be no problem with extensions, since these processors are supported in the latest systems, I can't wait to test this as soon as possible, I'm really not happy to have to wait again...
No, that is not entirely correct!

A lot of kernel extensions work based in the current board-id of the system. So the iMac 12,2 will remain a 12,2 and you can start you tour through the /System/Library/Extensions and patch the ID away. Another solution high be to spoof a 13,x or 14,x or better iMacPro1,1 ID using OpenCore to make the OS believe to have a more modern system. We are on our way to get a real Hackintosh system.

But you still need the UEFI firmware modified to boot a 2011 system board with a Ivy Bridge CPU. @Nick [D]vB planned to start this project back in late 2019, unfortunately he is missing here since May this year.
 
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StephN999

macrumors regular
Apr 12, 2020
182
110
Cergy, France
You're right I rushed, I still hope that the simple modification of the microcode will be enough...

I would patch the machine ID so that Istat Menu doesn't use the machines spoofed by OpenCore.

I hope we'll get some good news from @Nick [D]vB one day...

In any case as far as I'm concerned I expect my modification in about 10 days.
Keep your fingers crossed!
 
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cesarvog

macrumors member
Dec 22, 2009
33
13
Brazil
I currently have both a Xeon E3-1245v1 and a Nvidia Quadro K2100M waiting for some thermal pads to arrive in the mail, so I can start my iMac 2011 21.5" FrankeniMac revival.

From what I've read in this and several other threads, the original iMac 21.5" PSU won't be able to power both changes, so I got myself a spare iMac 2011 27" PSU ready in case it's needed... Won't fit, but I don't care if I have to somehow mount it on the outside. The machine was boxed in a closet for the last 3 years, so it's not much of a loss if everything goes to waste.

Therefore, for the sake of knowledge, I intend to proceed as follows:
1) Replace the Core i5 2400S with the Xeon E3-1245 with standard PSU and standard 21.5" AMD GPU. See if it posts, and if successful, verify if sleep, return from sleep works as expected (High Sierra with all security updates installed in the internal SSD (BTW, gone are the original 7.200 RPM HDD and the ODD).
2) Proceed with GPU replacement. See if it posts with original PSU. (Doubt it...) If succesful, load High Sierra and see if sleep still works. Once this has been stablished, go on and NVflash with @xanderon USB method using K2100.rom.
3) If everything above successful, verify sleep still works on High Sierra.

Leave it like that for a few days, so I can see if it is stable and run some benchmarks, test, whatever...

Of course, all of the above depend on the original PSU being able to support the additional wattage consumption of the replaced components. I suppose somewhere in the middle of all this, I will have to replace the PSU with the beefier one.

Once everything "settles", go on and try updating to Catalina with OpenCore and everyhing else I may need.

Do you experts believe this intended course is ok? Should I do anything else or in different order?

TIA
Cesar
 
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zabumbazarolha

macrumors newbie
Oct 8, 2020
4
5
Based on info from zabumbazarolha, I have updated post 1 to include that there is no evidence that any Xeon with integrated GPU can wake up from sleep. I think it is better to be conservative instead of giving false hope.

If anyone has any results to share on individual Xeons, please update post 1 with the results.

Apart from broken sleep, any other negative impact?
No, no... I'm really enjoying the performance. It had an increase from 2403 (i-5 2400 3.1 GHz) to 2936 on Geekbench 5. It's not much, I know, but overall I'm enjoying the result. The program I use (Archicad) had a reasonable improvement after the upgrade.
[automerge]1603311624[/automerge]
Unfortunately I have never found a single positive post about the fact that this CPU will not break sleep. Which OS version are you booting/using right now?
High Sierra.
 
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Ausdauersportler

macrumors 68000
Nov 25, 2019
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No, no... I'm really enjoying the performance. It had an increase from 2403 (i-5 3.4 GHz) to 2936 on Geekbench 5. It's not much, I know, but overall I'm enjoying the result. The program I use (Archicad) had a reasonable improvement after the upgrade.
[automerge]1603311624[/automerge]

High Sierra.
At least we know that this MacOS version does not need patching to provide proper sleep functionality with the original CPU. Mojave and Catalina and Big Sur need patching.

You possibly have to search the Hackintosh scene for a solution. Surely there are users having an older standard PC using your (new) CPU type?
 
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zabumbazarolha

macrumors newbie
Oct 8, 2020
4
5
At least we know that this MacOS version does not need patching to provide proper sleep functionality with the original CPU. Mojave and Catalina and Big Sur need patching.

You possibly have to search the Hackintosh scene for a solution. Surely there are users having an older standard PC using your (new) CPU type?
I took a look at Tonymacx86 but found nothing specific about the E3s V1... I didn't look very carefully, but it's not a much discussed subject there... Like I said, I'm happy with the 1275 without sleep mode... (it cost me £32) I turn off the computer at night and everything is fine...
 
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Ausdauersportler

macrumors 68000
Nov 25, 2019
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You may watch you power bill, 220 working days times 12h times 200W equals to 528 kWh which cost here around 20 cent. This is 100 Euro just for a always burning CPU. My two iMac sleep well using less then a W per hour unless I wake them up...
 

zabumbazarolha

macrumors newbie
Oct 8, 2020
4
5
You may watch you power bill, 220 working days times 12h times 200W equals to 528 kWh which cost here around 20 cent. This is 100 Euro just for a always burning CPU. My two iMac sleep well using less then a W per hour unless I wake them up...
Yes, you are right. In my case I work on the computer almost all the time. The price difference between a Xeon and an i7-2600 is not so great if you consider the energy bills (~35 against ~75 on Aliexpress). In short: I ended up buying E3-1275 based on this belief that IGPUs were the problem, but as we have seen here, this is not the case. This Xeon is a great processor, but I would recommend purchasing an i7-2600 for anyone upgrading. Maybe in a few months I'll switch again, (and also a GTX 780M graphics card)... Another thing is if you're looking for a second hand 27" 2011 imac, it's better to look for an i7 at once: many times, if you have patience, you can get it for the same price (or less) than an i5.
 

Redox785

macrumors newbie
Oct 23, 2020
3
0
Hey guys, Id like to ask you as I can see youre all quite qualified here :) Today Im about to buy my first iMac 27 2011, and as everything, I want to tweak it a bit :)

Here are my questions if I may ask:

Is there any possibility to be actually running 1600MHz RAM on this iMac? Maybe after suitable CPU-swap ?

Then, Im thinking about putting in the K4100M/K5100M/GTX675MX, can I choose randomly on eBay or look for some specifics?
The same question with SSD drive :)

Thank you all in advance for your replying on this :)
 
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nathan991

macrumors newbie
Feb 28, 2020
17
2
Hey guys, Id like to ask you as I can see youre all quite qualified here :) Today Im about to buy my first iMac 27 2011, and as everything, I want to tweak it a bit :)

Here are my questions if I may ask:

Is there any possibility to be actually running 1600MHz RAM on this iMac? Maybe after suitable CPU-swap ?

Then, Im thinking about putting in the K4100M/K5100M/GTX675MX, can I choose randomly on eBay or look for some specifics?
The same question with SSD drive :)

Thank you all in advance for your replying on this :)

We should try to keep this thread on topic, but in short, no CPU swap will increase the clock speed your ram is able to run at. You are limited to 1333MHz on this machine.

Check the 2011 iMac GPU Upgrade Thread on this forum for info on the GPU.

Only SATA SSDs will run on this machine and at max SATA III speeds.
 
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cesarvog

macrumors member
Dec 22, 2009
33
13
Brazil
Ok, part I of the iMac 12,1 (21.5") upgrade completed.
Core i5 S2400S replaced with Xeon E3-1245v1, as per below picture.
Computer does not recover from Deep Sleep, as expected, even though processor has an integrated Intel GPU. Therefore, there is no reason to go with the E3-12x5 variants, as it consumes more power and gives no additional benefit.

IMG_1921.jpeg

Next we will try to replace the stock AMD Radeon HD 6750M GPU with the Nvidia Quadro K2100M.

By the way, since the iMac 12,1 power supply can only deliver 210W, I originally thought it would be possible to replace the 12,1 PSU with the 12,2 PSU, which is capable of 310W. Well, apart from the obvious different dimensions, which did not bother me even if I had to somehow mount it on the outside of the case, I learned that there is also a difference in the PSU DC connector. The 12,1 PSU DC connector has only 14 pins, while the 12,2 PSU connector has 16, so there is no guarantee that each pin position deliver the same expected volts. Because of that, I intend to try the Xeon E3-1245v1 AND the Nvidia Quadro K2100M with the stantard 12,1 PSU. I'm almost sure it won't work...

Will report back as soon as I successfully replace the GPU. Stay tuned...
 
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StephN999

macrumors regular
Apr 12, 2020
182
110
Cergy, France
We should try to keep this thread on topic, but in short, no CPU swap will increase the clock speed your ram is able to run at. You are limited to 1333MHz on this machine.
Bonsoir,

I don't want to say stupidity but since it's the CPU that manages the memory, if my modification works the RAM in 1600Mhz will have to work too, I would like to test 1600Mhz in ECC precisely, if it works...

To be confirmed.🤞

Otherwise I have a vague memory that some rare people were surprised to see this machine with new RAM strips working in 1600Mhz, but maybe it's my memory that is biased. o_O
 

Redox785

macrumors newbie
Oct 23, 2020
3
0
Bonsoir,

I don't want to say stupidity but since it's the CPU that manages the memory, if my modification works the RAM in 1600Mhz will have to work too, I would like to test 1600Mhz in ECC precisely, if it works...

To be confirmed.🤞

Otherwise I have a vague memory that some rare people were surprised to see this machine with new RAM strips working in 1600Mhz, but maybe it's my memory that is biased. o_O
Hello Sir, so you're saying basically that if Ill upgrade to i7 2600, I should be able to have RAM on 1600MHz ?
 
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