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b4mb1

macrumors newbie
Original poster
Jan 13, 2020
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Hello,

I'm using an iMac Mid 2011 21.5" Yosemite (10.10.5) with Intel Core i5 (2.5Ghz) // 4GB 1333MHz // Radeon 6750M 512MB, and planning to upgrade these to:
  • Intel Core i7 2600S (2.8 GHz)
  • 32GB RAM (4x 8GB PC3-10600 DDR3 1333MHz)
  • 500GB Samsung SSD Primary | Change optical drive to 500GB HDD/SSD Caddy (for more storage)
  • Then after upgrades will update MACOSX to High Sierra (10.13)
My questions:
  1. Do I need a specific firmware for my iMac to recognize 32GB upgrade?
  2. Is there any way to allocate more VRAM to my GPU after my 32GB upgrade? Say for example: I want to allocate 2GB for my GPU from my RAM. Is it possible?
  3. Will I have any problems with the upgrades? Please let me know if there's cautions before upgrading. Thanks, guys!
 
You can add a second 2.5" SSD without replacing your optical drive, as there is a 2nd unused SATA socket and power socket on the back of the logic board, and you can buy the cables to fit these sockets.
If you replace the original Apple main HDD you will need an additional temperature sensor kit to keep the cooling stable.
The VRAM is soldered to the graphics card so cannot be increased except by fitting a different graphics card which has more VRAM.
 
You can add a second 2.5" SSD without replacing your optical drive, as there is a 2nd unused SATA socket and power socket on the back of the logic board, and you can buy the cables to fit these sockets.
If you replace the original Apple main HDD you will need an additional temperature sensor kit to keep the cooling stable.
The VRAM is soldered to the graphics card so cannot be increased except by fitting a different graphics card which has more VRAM.

Thanks for the reply. Regarding GPU, I've researched that almost every GPU that's available for this specific iMac are not plug in play or has no pre installed drivers for Mac in it. Is it possible to be like CPU whereas you just change it and your good to go?

EDIT:
Also, if I exchange the stock primary HDD to SSD, will I have any problems? I mean, from what I'm seeing on YouTube, they just exchange the primary drive with SSD then all is well. And also on the secondary SATA port, I will need a cable and a power connector for that, right? Any specifics for that one? Thanks.
 
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Can you boot from the ssd once installed if leaving the original HDD in place?
 
Will I have any problems with the upgrades? Please let me know if there's cautions before upgrading. Thanks, guys!

Double check your the voltage of your existing RAM modules (i.e. are they 1.5V or 1.35V). Macs are extremely fussy about this and, even if you have the other RAM specs perfect, your new RAM will be rejected if the voltages don't match.
 
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Can you boot from the ssd once installed if leaving the original HDD in place?
I haven't tried this yet. But I replaced the old HDD with a new SSD and it's working like a charm. But when I'm gonna execute the upgrade, I will buy a new HDD (Macs Fan Control solves the fan speed issue) with more space/speed, and move the SSD to the secondary SATA port then place the SSD below the ODD.

Double check your the voltage of your existing RAM modules (i.e. are they 1.5V or 1.35V). Macs are extremely fussy about this and, even if you have the other RAM specs perfect, your new RAM will be rejected if the voltages don't match.
I'm not sure how to check the sensors but this is my readings from iStat menus.

2020-01-26_10-51-05.png


If this ain't the sensors you're looking for, what is the program to check the voltage of the RAM? And by the way, this is the RAM I'm about to buy and everything looks exactly the same as required for this specific iMac.
 
This is an Ebay listing here showing your selected RAM as 1.35V.


The RAM inside your system could easily be 1.5V.

Looking on Amazon - a lot of the listings for iMac mid-2011 RAM - are for 1.5V RAM.

There is no program, that I'm aware of, that can tell you the RAM's voltage - you physically have to take old RAM modules out first to confirm.
 
Just upgraded my iMac 21,5 mid 2011, from I5 2400s to i7 2600s, ram from 8Gb to 16Gb, HDD to Ssd 480Gb. Cinebench 2.0 score go up on CPU from 775 to 1131, HDD To Ssd score from write 100,5 MB/sec to 457,5MB/sec, read from 125,5 MB/Sec to 529,90MB/sec.! Waiting for my MXM GPU card (Nvidia GTX 765M, 2Gb) to be replace the AMD Radeon HD 6750M 512 MB.
 
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This is an Ebay listing here showing your selected RAM as 1.35V.


The RAM inside your system could easily be 1.5V.

Looking on Amazon - a lot of the listings for iMac mid-2011 RAM - are for 1.5V RAM.

There is no program, that I'm aware of, that can tell you the RAM's voltage - you physically have to take old RAM modules out first to confirm.
I'll check the RAM inside my iMac later. I also contacted the seller from the store if what is the specific voltage of the RAM I'm about to buy. Thanks for the heads up.

Just upgraded my iMac 21,5 mid 2011, from I5 2400s to i7 2600s, ram from 8Gb to 16Gb, HDD to Ssd 480Gb. Cinebench 2.0 score go up on CPU from 775 to 1131, HDD To Ssd score from write 100,5 MB/sec to 457,5MB/sec, read from 125,5 MB/Sec to 529,90MB/sec.! Waiting for my MXM GPU card (Nvidia GTX 765M, 2Gb) to be replace the AMD Radeon HD 6750M 512 MB.
Nice. That's exactly what I'm gonna do. I can't find any GTX 765M on the online stores in my Location. However when I checked eBay, there's a listing with a GTX 765M 2GB from an Alienware laptop. I wonder if it's gonna work on our iMac.
 
I'll check the RAM inside my iMac later. I also contacted the seller from the store if what is the specific voltage of the RAM I'm about to buy. Thanks for the heads up.


Nice. That's exactly what I'm gonna do. I can't find any GTX 765M on the online stores in my Location. However when I checked eBay, there's a listing with a GTX 765M 2GB from an Alienware laptop. I wonder if it's gonna work on our iMac.
 
If I order this, is it plug n play? Or there will be requirements for this to be completely compatible with our iMac?

This is an Ebay listing here showing your selected RAM as 1.35V.


The RAM inside your system could easily be 1.5V.

Looking on Amazon - a lot of the listings for iMac mid-2011 RAM - are for 1.5V RAM.

There is no program, that I'm aware of, that can tell you the RAM's voltage - you physically have to take old RAM modules out first to confirm.
UPDATE:
I'm certain its 1.5v because when I grabbed the one from my iMac, it doesn't show any voltage reading. However, when I searched the make and model on Amazon, this showed up. It has the same model number, make, and has information that it's 1.5v
 
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The graphics card is NOT plug and play. when you install the card it will work, but you don't have a bootscreen, so you can not boot other HDD/SSD, the rest will work. There is a fix, but you have to read the discussion on this forum, see "2011 iMac graphics card upgrade" and there you find a fix for the bootscreen.
Also there is a youtube film where they install the card on a iMac 2010! If you have iMac mid 2011 Model 12,1 you have to take the logic board out!!
.
 
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The graphics card is NOT plug and play. when you install the card it will work, but you don't have a bootscreen, so you can not boot other HDD/SSD, the rest will work. There is a fix, but you have to read the discussion on this forum, see "2011 iMac graphics card upgrade" and there you find a fix for the bootscreen.
Also there is a youtube film where they install the card on a iMac 2010! If you have iMac mid 2011 Model 12,1 you have to take the logic board out!!
.

Thanks for the info, man. I think I won't have any problems with the hardware installation. I'm gonna research more about this boot screen workaround. Anyway, let me know after you upgraded your GPU. I'd like to hear your insight after your installation. Thanks!
 
Hello,

I'm using an iMac Mid 2011 21.5" Yosemite (10.10.5) with Intel Core i5 (2.5Ghz) // 4GB 1333MHz // Radeon 6750M 512MB, and planning to upgrade these to:
  • Intel Core i7 2600S (2.8 GHz)
  • 32GB RAM (4x 8GB PC3-10600 DDR3 1333MHz)
  • 500GB Samsung SSD Primary | Change optical drive to 500GB HDD/SSD Caddy (for more storage)
  • Then after upgrades will update MACOSX to High Sierra (10.13)
My questions:
  1. Do I need a specific firmware for my iMac to recognize 32GB upgrade?
  2. Is there any way to allocate more VRAM to my GPU after my 32GB upgrade? Say for example: I want to allocate 2GB for my GPU from my RAM. Is it possible?
  3. Will I have any problems with the upgrades? Please let me know if there's cautions before upgrading. Thanks, guys!
Seems a lot of money to spend on an iMac that will likely lose OS support (High Sierra) sometime this year. I have the same iMac and upgraded to an SSD and more RAM some years ago now. However, given it's age I won't be spending anything else on this machine. Something to consider.
 
Seems a lot of money to spend on an iMac that will likely lose OS support (High Sierra) sometime this year. I have the same iMac and upgraded to an SSD and more RAM some years ago now. However, given it's age I won't be spending anything else on this machine. Something to consider.
Don't know how much you payed for you're upgrade, but i was not more than 115 euro's for my upgrade, ssd 480 GB, 16gb ram, and i7 CPU. replaced the coolingpast on CPU and GPU and the imac works very fast.
 
Hi do you think the i7-4770S still work for my iMac 21,5? 65W too. That’s the i7 of the late 2013 iMac, and soon I put the 765M GPU the GPU of 27” iMac 2013 too. (Sorry for my bad English, from France)
 
Don't know how much you payed for you're upgrade, but i was not more than 115 euro's for my upgrade, ssd 480 GB, 16gb ram, and i7 CPU. replaced the coolingpast on CPU and GPU and the imac works very fast.
As said in my previous post I did the upgrades quite a few years ago now, did the work myself. However, items such as a Samsung Evo weren't cheap at the time and neither was RAM. The machine is still going strong, but given its age I wouldn't consider doing it now as it wouldn't be money well spent, especially given it's likely to lose OS support sometime this year.
 
As said in my previous post I did the upgrades quite a few years ago now, did the work myself. However, items such as a Samsung Evo weren't cheap at the time and neither was RAM. The machine is still going strong, but given its age I wouldn't consider doing it now as it wouldn't be money well spent, especially given it's likely to lose OS support sometime this year.

When i have my ordered grafics card, i'm going to install Catalina. So witch lose of OS support???
I'm already working on my Mac Pro 3,1 with Catalina and working fine. ;)
 
for everybody who want upgrade the memory: only use two modules(2x 8GB / 2x 16GB), because i noticed with 4 modules the mac runs with 2T command, with 2 modules he runs with 1T... why?: because depending on the programm u use, u will lose between 5-10% :(
 
for everybody who want upgrade the memory: only use two modules(2x 8GB / 2x 16GB), because i noticed with 4 modules the mac runs with 2T command, with 2 modules he runs with 1T... why?: because depending on the programm u use, u will lose between 5-10% :(
Interesting as i was about to chuck two more modules into one i have just acquired... many of the clips i have seen on YT they just pop additional modules in with no issues
 
When i have my ordered grafics card, i'm going to install Catalina. So witch lose of OS support???
I'm already working on my Mac Pro 3,1 with Catalina and working fine. ;)
Well given all the problems/issues regarding getting a good experience when attempting to install a newer GPU it's not something I am interested in, so good luck with that. I also have a 2019 27inch iMac, so when the 2011 one finally starts to die then I will simply remove the SSD and take it to the recycling centre.
 
Interesting as i was about to chuck two more modules into one i have just acquired... many of the clips i have seen on YT they just pop additional modules in with no issues

yeah, works fine, but 4 moduls u will pay with less performance(just interesting when u work with photoshop, video cutting or gaming, where all need every nanosecond they can get.
 
Schermafbeelding 2021-12-20 om 21.54.45.png


Still haven't time to put the graphic's card (GTX 765M 2 Gb) into my iMac 21,5" mid 2011, but I installed Monterey 12.1 with OpenCore Patcher. It works guit good, little problems are solved ,(wifi wasn't working, is now working!) only some small graphics issue, like split screen not working, but that is not disturbing for me. I think that is the standard graphic's card has no Metal support and hopefully that will be gone with the GTX 765M card. More info later. Merry Christmas
 
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Still haven't time to put the graphic's card (GTX 765M 2 Gb) into my iMac 21,5" mid 2011, but I installed Monterey 12.1 with OpenCore Patcher. It works guit good, little problems are solved ,(wifi wasn't working, is now working!) only some small graphics issue, like split screen not working, but that is not disturbing for me. I think that is the standard graphic's card has no Metal support and hopefully that will be gone with the GTX 765M card. More info later. Marry Christmas
Installed the Nvidia GTX 765M, boot normal, but is very slow, Monterey 21,1 didn't see the graphic card right, sees it as a videocard with 8(MB!!!!!),doesn't see the card as a Nvidia GTX 756M 2GB :mad:. Installed the AMD Radeon HD 6750M 512MB back and works oke!!.
 
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