Hardware Ignoramus, need help upgrading my RAM

I own a pre-built workstation and would like to install 4 additional GB of RAM (currently have 12). My workstation model is HP Z400.

Based on these specifications (http://www.hp.com/canada/products/landing/workstations/files/13276_na.pdf), I would guess that any 4GB DDR3-1333 Ram would work, but I'm way too clueless to just purchase one and give it a try.

Could you please help me out? I've done a bit of research but I feel like I really need some external help from someone more knowledgeable...

Submitted May 16, 2018 at 08:39PM by cartmancoma https://ift.tt/2k05fAc