Question about OWC 8.0GB 1600MHz DDR3 memory for iMac 27

I understand the RAM memory OF the 27 inch and 21.5 inch iMAC is the SAME.

According to memorystick.com - these are the same RAM MEMORIES:
https://www.memorystock.com/
iMAC 27" late 2012 uses : 8GB DDR3 PC3-12800 204pin CL=11 DDR3-1600 1.5V SODIMM, MemoryStock Part# 869ms-869
iMAC 21.5 late 2013 uses: 8GB DDR3 PC3-12800 204pin CL=11 DDR3-1600 1.5V SODIMM, MemoryStock Part# 869ms-869

As per Apple site the 2012 27 INCH iMAC uses: Small Outline Dual Inline Memory Modules (SO-DIMM) that meet all of these criteria:
PC3-12800, Unbuffered, Nonparity, 204-pin, 1600MHz DDR3 SDRAM. As per Apple site the 2013 21.5 INCH iMAC uses the SAME 8GB of 1600MHz DDR3 memory

HOWEVER, the installation AND the MAX RAM WHICH CAN BE INSTALLED IS DIFFERENT!
The 2012 27 INCH HAS FOUR SLOTS 8X4 = 32 GB max. The 2013 21.5 INCH HAS TWO SLOTS 8x2 = 16 GB RAM.

As per Apple site:
the 2012 27 INCH iMAC can be upgraded to 32 GB RAM memory https://support.apple.com/en-us...
the 2013 21.5 INCH iMAC can be upgraded to 16 GB RAM memory. https://support.apple.com/kb...

For the 27 INCH iMAC the upgrade is doable for regular "users".
The 21.5 inch iMAC has a more difficult installation for "sophisticated, technical specialists only" where the screen needs to be removed e.g. via an old credit card. Then special tools are used to remove other components until the logic board can be removed where the RAM MEMORY IS REPLACEINSTALLED.
https://www.youtube.com/watch

One feedback I collected from the internet: Yes, iMacs use the same standard SO-DIMM RAM which is used in many laptops, just be sure to buy the same kind specified in the Apple menu "About This Mac". The 21.5” models comes without the access panel to get to the ram, only the 27” models have the ram slots accessible externally in the rear. For cutting the adhesive in order to open the iMac, I used an old credit card (almost any plastic card could work as opener), I just sharpened one of its corners and worked perfectly. Review these two guides iMac Intel 21.5" EMC 2638 Display Replacement & iMac Intel 21.5" EMC 2638 Adhesive Strips Replacement. Mar 17, 2020 by Roy Lopez

All the Best,
Gregor G. Gimmel

I don't know. I installed on iMAC 27'' 2012 and it works fine.