Solved: Z400 RAM - Page 2 - HP Support Community - 6148900
Norton Racing Ninja400R Ram Air Kit - Kawasaki Ninja 400 / Z400
Hp Z 400 mixed ram - HP Support Community - 7621103
CMS 12GB (3X4GB) DDR3 10600 1333MHZ ECC Non Registered DIMM Memory Ram Upgrade Compatible with HP/Compaq® Workstation Z200, Z210, Z400, Z600, Z800 for Server Only - B81 at Amazon.com