HP Z400 Workstation
Desktop, from 2009 57 hardware reports
Memory

Up to 24 GB
6 full-size slots
Drives and power
Coming next
Checked from separate sources
Upgradable
Yes. 6 slots, up to 24 GB seen working.
It takes DDR3-1333 full-size sticks (DIMM).
- Slots
- 6 DIMM slots
- Type
- DDR3-1333 240-pin DIMM
- Most seen working
- 24 GB in two or more machines; one machine runs 48 GB 0
- How sure
- 52 of 57 reports show this layout
See 4 GB DDR3-1333 DIMM on AmazonOpens an Amazon search for this exact spec.
Worked out from 57 hardware reports of this desktop. Sources and method. Updated 9 Nov 2026.

6 full-size slots
Illustration Questions
Can I upgrade the RAM in the HP Z400 Workstation?
Yes. 6 slots, up to 24 GB seen working. It takes DDR3-1333 full-size sticks (DIMM).
What type of RAM does the HP Z400 Workstation use?
DDR3-1333 full-size sticks (DIMM, 240-pin).
How much RAM can the HP Z400 Workstation take?
Machines in the reports run up to 24 GB, and one runs 48 GB.
Is this my desktop?
Check the model name on the front or the label of the case. It should read Z400 Workstation.