Apple iMac (20-inch and 24-inch, Early and Mid 2009)
Model identifier iMac9,1 All-in-one, from 2009 97 hardware reports
Upgradable
Yes. 2 slots, up to 8 GB seen working.
It takes DDR3-1066 laptop-size sticks (SO-DIMM).
- Slots
- 2 SO-DIMM slots
- Type
- DDR3-1066 204-pin SO-DIMM
- Most seen working
- 8 GB in two or more machines
- Firmware says
- 32 GB maximum (often wrong, so we show what machines run)
- How sure
- 28 of 28 reports show this layout
See 4 GB DDR3-1066 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.
2 laptop-size slots
Illustration Questions
Can I upgrade the RAM in the Apple iMac (20-inch and 24-inch, Early and Mid 2009)?
Yes. 2 slots, up to 8 GB seen working. It takes DDR3-1066 laptop-size sticks (SO-DIMM).
What type of RAM does the Apple iMac (20-inch and 24-inch, Early and Mid 2009) use?
DDR3-1066 laptop-size sticks (SO-DIMM, 204-pin).
How much RAM can the Apple iMac (20-inch and 24-inch, Early and Mid 2009) take?
Machines in the reports run up to 8 GB. The firmware reports a maximum of 32 GB, a figure that is often wrong.
Is this my desktop?
On the Mac, choose Apple menu > About This Mac > System Report. The Model Identifier should read iMac9,1.
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