Apple iMac (Retina 5K, 27-inch, 2019)
Model identifier iMac19,1 All-in-one, from 2019 38 hardware reports
Upgradable
Yes. 4 slots, up to 64 GB seen working.
It takes DDR4-2666 laptop-size sticks (SO-DIMM).
- Slots
- 4 SO-DIMM slots
- Type
- DDR4-2666 260-pin SO-DIMM
- Most seen working
- 64 GB in two or more machines; one machine runs 88 GB
- Firmware says
- 64 GB maximum
- How sure
- 28 of 28 reports show this layout
See 16 GB DDR4-2666 SO-DIMM on AmazonOpens an Amazon search for this exact spec.
Worked out from 28 hardware reports of this desktop, with Apple's memory specifications for which Macs have sockets. Sources and method. Updated 10 Nov 2026.
4 laptop-size slots
Illustration Questions
Can I upgrade the RAM in the Apple iMac (Retina 5K, 27-inch, 2019)?
Yes. 4 slots, up to 64 GB seen working. It takes DDR4-2666 laptop-size sticks (SO-DIMM).
What type of RAM does the Apple iMac (Retina 5K, 27-inch, 2019) use?
DDR4-2666 laptop-size sticks (SO-DIMM, 260-pin).
How much RAM can the Apple iMac (Retina 5K, 27-inch, 2019) take?
Machines in the reports run up to 64 GB, and one runs 88 GB. That matches the 64 GB maximum the firmware reports.
Is this my desktop?
On the Mac, choose Apple menu > About This Mac > System Report. The Model Identifier should read iMac19,1.
More in the Apple iMac
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