ProDesk 405 G4 RAM upgrade, mixed information's on whether its DIMM or UDIMM

[make_IT_happen]

I bought an ProDesk 405 G4 on ebay, and want to upgrade the RAM but i have mixed information's on whether its DIMM or UDIMM, how to find out remotely? I have no access to the PC right now because it will take time for it to arrive.

In this document https://h20195.www2.hp.com/v2/GetDocument.aspx?docname=c06500694&cc=at&lc=de

it states, in "AT A GLANCE"
• Supports up to 64GB DDR4-2666 Unbuffered Memory (UDIMM)

And further below in the document it stated:

"MEMORY"
Max Memory Configuration
DDR4-2666 (Transfer rates up to 2666 MT/s), 64 GB, 4 DIMM
Memory Configuration
4GB (1x4GB) 2666 DDR4 1.2v DIMM
8GB (2x4GB) 2666 DDR4 1.2v DIMM
8GB (1x8GB) 2666 DDR4 1.2v DIMM
16GB (2x8GB) 2666 DDR4 1.2v DIMM
16GB (1x16GB) 2666 DDR4 1.2v DIMM
32GB (2x16GB) 2666 DDR4 1.2v DIMM
32GB (4x8GB) 2666 DDR4 1.2v DIMM
64GB (4x16GB) 2666 DDR4 1.2v DIMM

So what's right now?

[Paul_Tikkanen · Accepted solution]

The terms are used interchangeably..

DIMM stands for Dual Inline Memory Module.

UDIMM is a full-sized memory chip used in most desktop PC's such as the 405 G4 SFF and MT.

SODIMM memory is the type used in notebook PC's and a few desktop PC's such as the 405 G4 Desktop MIni (DM).

If you bought a 405 G4 SFF or MT, then the PC uses UDIMM memory.

Crucial RAM 16GB DDR4 3200MHz CL22 (or 2933MHz or 2666MHz) Desktop Memory CT16G4DFRA32A at Amazon.co...

If you bought the 405 G4 DM, then that uses SODIMM memory:

Amazon.com: Crucial RAM 16GB DDR4 3200MHz CL22 (or 2933MHz or 2666MHz) Laptop Memory CT16G4SFRA32A :...