Dell OptiPlex 755
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
Worked out from 103 hardware reports of this desktop. Sources and method. Updated 10 Nov 2026.
It takes a 2.5-inch SATA SSD.
The machines in the reports have a SATA controller. A 2.5-inch SATA SSD fits a 2.5-inch bay, or a 3.5-inch bay with an adapter bracket.
- Drive type
- SATA
From 207 PCI device reports. Sources and method. Updated 10 Nov 2026.
Illustration Check the label on the power supply.
We don't have this model's power supply rating. It is printed on the supply's sticker, inside the case next to its fan. Prebuilt desktops often use a supply shaped for their case, so match the shape and the plugs as well as the watts. Small cases take a slim supply.
- Rating
- On the supply's label
How to read a power supply label. Sources and method. Updated 10 Nov 2026.
Illustration It takes processors for the LGA775 socket.
Prebuilt desktops often only take processors from the generation they shipped with, so stay with the ones listed.
- Socket
- LGA775
- How sure
- From 0 report
From the processor records in 0 hardware report. Sources and method. Updated 10 Nov 2026.
Illustration People run graphics cards in this desktop.
Cards in the reports: Radeon HD 2400 PRO/XT (10), GeForce GT 610 (8), GeForce 210 (7), GeForce GT 710 (6), GeForce 8400 GS Rev. 3 (4), Radeon HD 6450/7450/8450 / R5 230 OEM (4). 72% of these machines report a small case. A small case takes low-profile cards only, and its power supply may not feed a card that needs its own power cable.
- Seen working
- Radeon HD 2400 PRO/XT, GeForce GT 610, GeForce 210
- Case
- 72% report a small case
From 211 PCI device reports. Sources and method. Updated 10 Nov 2026.
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.
What SSD does the Dell OptiPlex 755 take?
It takes a 2.5-inch SATA SSD. The machines in the reports have a SATA controller. A 2.5-inch SATA SSD fits a 2.5-inch bay, or a 3.5-inch bay with an adapter bracket.
What processor can I put in the Dell OptiPlex 755?
It takes processors for the LGA775 socket. Prebuilt desktops often only take processors from the generation they shipped with, so stay with the ones listed.
Can I add a graphics card to the Dell OptiPlex 755?
People run graphics cards in this desktop. Cards in the reports: Radeon HD 2400 PRO/XT (10), GeForce GT 610 (8), GeForce 210 (7), GeForce GT 710 (6), GeForce 8400 GS Rev. 3 (4), Radeon HD 6450/7450/8450 / R5 230 OEM (4). 72% of these machines report a small case. A small case takes low-profile cards only, and its power supply may not feed a card that needs its own power cable.
Is this my desktop?
Check the model name on the front or the label of the case. It should read OptiPlex 755.