Server Que.: More Capacity vs. Triple Channel

[PliotronX]

Hey guys so this company really wants "moar RAAHHM" and I'm trying to concretely find out how much the added bandwidth matters of triple channel. They currently have 24GB in 3x8 and so simply throwing another 8GB in there will work fine but only in dual channel. Now I've found out they want to max out the slots so it'd be 64GB in 8x8 which would still be dual channel. Is it worth pressing for triple channel?

 

[DominionSeraph]

What socket is this? LGA2011 is quad-channel, and LGA1366 shouldn't have 8 slots.

 

[PliotronX]

Well s*** now that you mention it, what's the black colored slot for? It's a PowerEdge T410 (LGA1366):

 

[KentState]

Probably some type of redundancy.

 

[PliotronX]

Interesting! Well that settles that, six slots will make this easy! Thank you guys :thumbsup:

 

[imagoon]

That system can only use 4 slots, the set above CPU0. The other 4 slots are for CPU1 which is not populated in your system. The max that one can support is 8GBx4 RDIMM DDR3. Their is a tech note about 16GB quad RDIMMs but I am not sure if it needs a BIOS update.

Tech specs for every server Dell sells is on their site:

http://www.dell.com/downloads/globa...erver-poweredge-t410-technical-guide-book.pdf

 

[PliotronX]

That system can only use 4 slots, the set above CPU0. The other 4 slots are for CPU1 which is not populated in your system. The max that one can support is 8GBx4 RDIMM DDR3. Their is a tech note about 16GB quad RDIMMs but I am not sure if it needs a BIOS update.

Tech specs for every server Dell sells is on their site:

http://www.dell.com/downloads/globa...erver-poweredge-t410-technical-guide-book.pdf

Such an awesome link, thank you! It does look like slots 1 and 4 share channel 0, and so we are also looking at throwing another Xeon in there which will enable the second set of banks with a BIOS update, no? Are these slots redundant with CPU0's RAM or will they pool the RAM? Definitely have a better understanding, I appreciate it. We will have to replace those 8GB RDIMM's regardless.

 

[gbeirn]

Such an awesome link, thank you! It does look like slots 1 and 4 share channel 0, and so we are also looking at throwing another Xeon in there which will enable the second set of banks with a BIOS update, no? Are these slots redundant with CPU0's RAM or will they pool the RAM? Definitely have a better understanding, I appreciate it. We will have to replace those 8GB RDIMM's regardless.

A few Socket 1366 boards came with 4 slots. Basically three of them will operate in triple channel and the last single channel. So if for example you had 4x4GB chips in there, the first 12GB would operate in triple channel and the last 4GB in single.

A second CPU would allow use of the other RAM slots, yes. No BIOS update needed I would guess. By default the exact RAM should just show up so 4x4GBx2 CPUs would show 32GB total. There may be options in the BIOS to do memory mirroring or things like that that would cut down on the available RAM but you would have to turn those on.

 

[imagoon]

The BIOS update comment was only for 16GB RDIMM support if it was needed. Even though the RAM is directly attached to a certain CPU, they will allow any CPU access to the RAM via the transport links that connect the memory controllers together.

--edit--

One thing to be aware of is DIMM ranks. When I said "Quad 16GB DIMM" I actually meant a 4 rank 16GB RDIMM. You could put 4 of those in that server if the tech note I saw says it is supported. I think the note said a supported max RAM of 128GB with 8 x 16GB 4 rank RDIMMs.