I have a Dell R710 that's refurbished (so no warranty or support by Dell) and currently has 48 GB of RAM in it (12x4GB). According to the smbiosDump
in ESXi, it looks like this:
# smbiosDump | egrep '(Number:|Location)'
Location: "DIMM_A1"
Part Number: "36JSZF51272PZ1G4F1"
Location: "DIMM_A2"
Part Number: "36JSZF51272PZ1G4F1"
Location: "DIMM_A3"
Part Number: "HMT151R7BFR4C-H9"
Location: "DIMM_A4"
Part Number: "36JSZF51272PZ1G4F1"
Location: "DIMM_A5"
Part Number: "36JSZF51272PZ1G4F1"
Location: "DIMM_A6"
Part Number: "M393B5170EH1-CH9"
Location: "DIMM_A7"
Location: "DIMM_A8"
Location: "DIMM_A9"
Location: "DIMM_B1"
Part Number: "36JSZF51272PZ1G4F1"
Location: "DIMM_B2"
Part Number: "36JSZF51272PZ1G4F1"
Location: "DIMM_B3"
Part Number: "HMT151R7BFR4C-H9"
Location: "DIMM_B4"
Part Number: "36JSZF51272PZ1G4F1"
Location: "DIMM_B5"
Part Number: "36JSZF51272PZ1G4F1"
Location: "DIMM_B6"
Part Number: "M393B5170EH1-CH9"
Location: "DIMM_B7"
Location: "DIMM_B8"
Location: "DIMM_B9"
As you can see, I have 6 open slots on the board so an entire channel is free for use. I'm currently using the "Optimized" mode, which according to the manual means I can fill this third channel with additional RAM.
I noticed that there's 3 different part numbers for the RAM on this server. These two (M393B5170EH1-CH9 and HMT151R7BFR4C-H9) appear to by Hynix RAM which is compatible. The third one is an unknown Samsung that I can't find anywhere.
So, my question is this: If I were to purchase additional RAM (the Hynix one linked above), is it safe to say that this will work? The manual for compatibility is confusing, so I want to get this right. I had purchased Corsair RAM (8 GB, 4xr8, 1333Mhz, ECC) but the server rejected it when I installed them, so I'd like to avoid repeating my mistake!
I would search on the official Dell part number. It's not about the OEM for RAM like this. It's about the compatible part numbers (from Dell's perspective).
Buy SNPX3R5MC/8G.
This question is on the borderline of shopping, but I can tell you our experience with those servers.
Dell, like any other server vendor, wants your unborn children for upgrades after you've bought a server. My solution was to replace all the RAM in the system with Kingston system-specific memory, which have a lifetime guarantee and is 100% compatible.
Note that it will probably void any kind of support agreement you have, so I would keep the old RAM sticks around and install them if you ever need a onsite support engineer from Dell.
A word of caution: Triple-channel is not recommended on these servers, as it will lower your bus speed. Using quad rank modules makes it even worse (down from 1333mhz to 800mhz). This has a rather substantial impact on environments where there is a large amount of memory usage (virtualization, databases etc). I would go for 16GB Dual Rank modules, which should give you a nice upgrade to 192GB with 2 CPU's installed.