Dell OptiPlex 755
Desktop, from 2007 103 hardware reports
Memory

Up to 8 GB
4 full-size slots
SSD, drives and power
Coming next
Checked from separate sources
Upgradable
Yes. 4 slots, up to 8 GB seen working.
It takes DDR2-667 full-size sticks (DIMM).
- Slots
- 4 DIMM slots
- Type
- DDR2-667 240-pin DIMM
- Most seen working
- 8 GB in two or more machines
- Firmware says
- 8 GB maximum
- How sure
- 95 of 103 reports show this layout
See 8 GB DDR2-667 DIMM on AmazonOpens an Amazon search for this exact spec.
From 103 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 755?
Yes. 4 slots, up to 8 GB seen working. It takes DDR2-667 full-size sticks (DIMM).
What type of RAM does the Dell OptiPlex 755 use?
DDR2-667 full-size sticks (DIMM, 240-pin).
How much RAM can the Dell OptiPlex 755 take?
Machines in the reports run up to 8 GB. That matches the 8 GB maximum the firmware reports.
Is this my desktop?
Check the model name on the front or the label of the case. It should read OptiPlex 755.