Dell Server PowerEdge R320 RAM upgrade

wheezer

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I JUST got off the phone with a Dell parts rep, looking for upgrades for our one year old PowerEdge R320, and by now I am so damned confused I could spit... Because I trust in what I read here on Tom's Hardware, I'm turning to someone on this forum who might actually KNOW ..
Can anyone tell me what the actual RAM 'specs' are for our PowerEdge R320 (model PER320) currently running Windows Server 2012 Essentials (64-bit OS)...? My interest is in what the parts rep told me: that the currently installed 8 GB of RAM (2X4GB DDR3-1333) MUST be replaced with 4 X 8GB DDR3-1333 if we want to increase system memory to something like 24-32 GB of RAM ... And yet, the owner's manual states that "memory sizes CAN be mixed" so long as we 'match' the banks (6 slots on the M/B). He also stated that this system has a max. memory of just 96 GB when the manual clearly states the max. as 192 GB. So which is it..? Believe the parts rep or the manual which came with the system? Since we already have 8 GB in the first bank, can I not simply install two or four 'matched' 8 GB DIMMS in the remaining four slots? I understand that the RAM DIMMS should also match as regards 'ranks', which I see elsewhere (https://en.wikipedia.org/wiki/Memory_rank) as having to do with 'addressing' which makes sense that for a server, these should be matched - but 'overall' or simply by 'banks'..?
GAH!! The owner's manual states a compatibility with 'mixed RAM' but I think this is considered 'by banks' - but maybe not 'overall' when considering 'rank'...
I am so confused by this - but I don't want to adversely affect server performance either...
Sheesh! HELP!
 

kanewolf

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casper1973

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Server 2012 Essentials is limited to 64GB of RAM so it's somewhat irrelevant if your hardware supports 96GB or 192GB (spec sheet does say 192GB though).

EDIT:

I done some reading through the manual.


Your motherboard uses a dual channel memory controller. The channels are split as such

channel 1: memory sockets A1 and A4
channel 2: memory sockets A2 and A5
channel 3: memory sockets A3 and A6
see page 44. Manual was linked in previous post

The two sticks which make up a channel must be identical, but they don't have to match with other channels.
ie. A1+A4 must match with each other, but they don't have to match with A2+A5 or A3+A6

This means you could use 2x4GB in A1+A4 combined with 2x8GB in A2+A5.

Keep everything but capacity identical throughout (frequency, CAS latency, voltage, ECC, buffered/unbuffered)


Here is an extract from the manual which may also help.
-------------------------------------------------------------------------------
UDIMMs and RDIMMs must not be mixed.
• x4 and x8 DRAM based DIMMs can be mixed. For more information, see Mode-Specific Guidelines.
• A maximum of two UDIMMs can be populated in a channel.
• A maximum of two single- or dual-rank RDIMMs can be populated in a channel.
• Populate all sockets with white release tabs first, and then black.
• Populate the sockets by highest rank count in the following order - first in sockets with white release levers, and
then black. For example, if you want to mix quad-rank and dual-rank DIMMs, populate quad-rank DIMMs in the
sockets with white release tabs and dual-rank DIMMs in the sockets with black release tabs.
Memory modules of different sizes can be mixed provided that other memory population rules are followed (for
example, 2 GB and 4 GB memory modules can be mixed).

• Depending on mode-specific guidelines, populate two or three DIMMs per processor (one DIMM per channel) at a
time to maximize performance. For more information, see Mode-Specific Guidelines.
• If memory modules with different speeds are installed, they will operate at the speed of the slowest installed
memory module(s) or slower depending on system DIMM configuration
 

Deuce65

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Oct 16, 2013
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The original service manuals indicate 96gb limit because each slot could take a 16gb stick (6 slots). Somewhere along the line that was updated to 32gb per slot (I am assuming a bios update). I have no idea how long ago it was that this happened.
Of course, as others have pointed out it's a moot point....