Model Identifiers (AKA Model IDs) are an easy way to identify your Mac, which is particularly important if you’re planning to upgrade the memory or storage of your new or old device. During the compatibility testing to ensure that the new 2019 27-inch iMac could take as much as 128GB of memory, OWC engineers noticed a slight mixup when verifying the Model ID numbers for both the 27-inch and 21.5-inch models. Here is the correct Model ID from the 21.5-inch iMac:
And here’s the Model ID from the 27-inch iMac:
Looking closely at the System Information screen from both of the 2019 iMacs (see screenshots above), one can see that the 21.5-inch Retina 4K iMac has Model ID iMac 19,2 while the 27-inch Model ID is iMac 19,1. Apple’s support page for iMacs shows those Model IDs incorrectly swapped, with the 2019 21.5-inch iMac showing iMac 19,1 and the 27-inch model listed as iMac 19,2:
All we can think is that Apple must have been quite excited about the prospect of releasing two new and faster versions of the iMac! Without a doubt, they’ll fix the support page now that we’ve pointed out the error.
Model IDs are the best way to select the proper upgrades for your Mac. It’s easy to find the Model ID of any Mac:
Once you have that Model ID, it’s easy work to determine what OWC upgrades are available for your Mac. For memory upgrades, point your browser to the MacSales.com home page and hover your pointer over the word Memory. A list of Mac types appears; select the one for your particular type, then use the Model ID from System Report to find the memory upgrade for your Mac.
In a similar manner, the Model ID can be your guide for finding available storage (Solid-State Drives or Hard Disk Drives) for your Mac. Storage upgrades from OWC can be found on this page, and by selecting one of the categories of drives (3.5″ SATA Drives, 2.5″ laptop hard drives and SSDs, SSDs, Mac Pro drives, or 3.5″ IDE/ATA drives), you can quickly match the correct drive to your specific Mac model:
It’s great to see that Apple gets as thrilled with new hardware as we do. By the way, now that our compatibility testing is complete, you can purchase the following memory upgrades for the 27-inch Retina 5K iMac:
- 64GB (2 X 32GB) — $579.99
- 96GB (2 X 32GB + 2 X 16GB) — $749.99
- 128GB (4 X 32 GB) — $1099.99
It appears that Apple has finally corrected their database and my 27″ iMac is listed as one of my devices under my account on the Apple site instead of a 21.5″. I installed 64gb of memory and it shows up in the slots, but system report still states Upgradeable Memory: No.
A side effect of this mistake is that the 27″ 2019 iMac is said to have unupgradeable memory in the System Information window when it clearly does. It shows the empty slots. Added RAM shows up. Also the About this Mac window has no Memory tab. So basically it thinks it’s a 21.5″ which is not upgradable. Still I would have thought the memory tab would be visible.
Thanks for your article about the model id mixup. I just received my 27″ iMac today and it has 19,1 as the model identifier but my Apple account shows it as a 21.5″ as does iCloud. I called Apple, but they don’t seem to know anything.
Apple got something wrong? lol