HP Z440, Z640, and Z840 Workstation Series - Maintenance and Service Guide
HP Z840 Workstation DIMM installation order
Install DIMMs in this order.
NOTE: If you install DIMMs of dierent sizes, load them in order of size, starting with largest and nishing
with the smallest (largest in DIMM 1, smallest in last loaded DIMM slot).
68 Chapter 3 Component replacement information and guidelines