Dell OptiPlex 790
Desktop, from 2011 122 hardware reports
Memory
Up to 20 GB
4 full-size slots
SSD, drives and power
Coming next
Checked from separate sources
Upgradable
Yes. 4 slots, up to 20 GB seen working.
It takes DDR3-1333 full-size sticks (DIMM).
- Slots
- 4 DIMM slots
- Type
- DDR3-1333 240-pin DIMM
- Most seen working
- 20 GB in two or more machines
- Firmware says
- 32 GB maximum (often wrong, so we show what machines run)
- How sure
- 108 of 122 reports show this layout
See 4 GB DDR3-1333 DIMM on AmazonOpens an Amazon search for this exact spec.
From 122 reports of this machine in the Linux Hardware Database (CC BY 4.0). Updated 9 Nov 2026.
4 full-size slots
Illustration Questions
Can I upgrade the RAM in the Dell OptiPlex 790?
Yes. 4 slots, up to 20 GB seen working. It takes DDR3-1333 full-size sticks (DIMM).
What type of RAM does the Dell OptiPlex 790 use?
DDR3-1333 full-size sticks (DIMM, 240-pin).
How much RAM can the Dell OptiPlex 790 take?
Machines in the reports run up to 20 GB. The firmware reports a maximum of 32 GB, a figure that is often wrong.
Is this my desktop?
Check the model name on the front or the label of the case. It should read OptiPlex 790.