In a HP server, can low voltage DIMMS and standard voltage DIMMs be mixed

hphp-proliantmemory

We are adding RAM to a HP Proliant DL380 G7 and were shipped standard voltage DIMMS. We have pre-installed some low voltage DIMMS.

Is it acceptable to mix DIMM voltage in general? Is it advised?

A technician is attempting to do this now, but the server isn't booting past the fan start-up, and I suspect either the DIMM isn't properly seated, defective, or they are in the wrong slots. OR that I can't mix the DIMMS.

These DIMMS were recommended by HP so I'm thinking this should work.

New DIMMs

Qty

 3:   8gb 2rx4 pc3 10600r 9-12-e2

 9:   8gb 2rx4 pc3L 10600r 9-10-e1p1

Best Answer

Yes, this is possible, with a couple of caveats. Can you provide the specific DIMM sizes and their respective voltages?

In my experience, the one situation that causes a problem are certain 8Gb DIMMs and 16Gb low-voltage modules. Hynix (HP-branded) 8Gb DIMMS with heat shields will not post in this situation. Other HP 8Gb DIMMs will, even though they all have the same HP spare part number. It's an edge case, but impacted me on several dozen G7 servers in a large environment.