Dell OptiPlex 780

Desktop, from 2009 142 hardware reports
Memory
Up to 16 GB
4 full-size slots
SSD, drives and power
Coming next
Checked from separate sources
Upgradable

Yes. 4 slots, up to 16 GB seen working.

It takes DDR3-1066 full-size sticks (DIMM).

Slots
4 DIMM slots
Type
DDR3-1066 240-pin DIMM
Most seen working
16 GB in two or more machines
Firmware says
8 GB maximum (often wrong, so we show what machines run)
How sure
124 of 142 reports show this layout
See 4 GB DDR3-1066 DIMM on AmazonOpens an Amazon search for this exact spec.

From 142 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 780?

Yes. 4 slots, up to 16 GB seen working. It takes DDR3-1066 full-size sticks (DIMM).

What type of RAM does the Dell OptiPlex 780 use?

DDR3-1066 full-size sticks (DIMM, 240-pin).

How much RAM can the Dell OptiPlex 780 take?

Machines in the reports run up to 16 GB. The firmware reports a maximum of 8 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 780.