toys19 - Member
Also factor in if you fully populate a channel it down-clocks the DIMM speed so you can degrade performance (if memory speed is a bottleneck rather than just more available memory being required), this is why we pay a premium for large DIMM modules on servers so we don't fully populate
I think I need to understand this more?
I thought it was the exact opposite, that if there are empty DIMM slots then there is a portion of the channel that is not being used so its better to spread the memory over every channel rather than concentrate it on one..
IE we have 16 cores and 16 slots so its a essentially a slot for each core..
(I'm bound to be wrong about this, but I would appreciate any help in understanding whats what)
Totally depends on the server's architecture. I had a HP server a while back which had 12 slots per CPU, but to get the absolute fastest performance you need to use two lots of 4xquad ranked sticks for each CPU leaving 4 slots per CPU empty. Whether you need maximum performance or just more capacity depends on your application, more memory might be faster overall even if it is slightly slower (i.e. less swapping, more disk contents cached, DB indexes kept in RAM etc).
The other thing i forgot to mention is ECC. You will almost certainly need that to match what you already have (and it would be silly not to have it on a server TBH).
Why not just phone a couple of IT suppliers and get quotes using Dell's official part number? You won't necessarily be able to find places listing the number on google, but loads of people will stock it or its replacement if that part number is EOL.