Poweredge R610 memory expansion

Hello syuroff

No, that is not a valid configuration.

Per the manual, "In a dual-processor configuration, the memory configuration for each processor must be identical"- do I still qualify as identical if I add the same thing to both sides?

Yes, that is what it means. Both lanes/sides must be identical.

The reason the proposed configuration is invalid is because the DIMMs must be installed in pairs(Except for single DIMM troubleshooting configs). The other reason is that each bank must be populated by the same number of DIMMs. If you put 2 DIMMs in the first bank(1,2,3) then you either have to put two DIMMs in the second bank(4,5,6) or have no DIMMs installed in the second bank.

To make your proposed configuration work you will need to add two more 16GB DIMMs.

What would be the effect on Optimizer mode if I added these?  In the real world, will it matter?

It will still run in optimizer mode so there will be no change. The other thing to double check is whether your current DIMMS are registered or unregistered. The 16GB DIMMs only come in registered/buffered, and the two types cannot be mixed.

Thanks

By "pairs", does that mean a pair in each bank, where a "bank" is the group of 6 slots on each side?  Therefore, any and all RAM upgrades have to be in 4s?

(Sorry, I'm physically separated from the servers to look at them and see where the DIMMs are. I don't know where the DIMMs are... 6 on one side, 3 vs 3...)

How do I query the DIMMS for their registered/unregistered/buffered status?  Server(s) are running XenServer, FWIW.

Thanks for the guidance, you've already stopped me from doing something regrettable.

By "pairs", does that mean a pair in each bank, where a "bank" is the group of 6 slots on each side?

There are two lanes, one for each CPU. The 6 slots for CPU 1 are a lane and the 6 slots for CPU 2 are a lane. There are two banks in each lane. Slots 1,2,3 are one bank and slots 4,5,6 are the other bank. You need to install in pairs within a bank, but because you are running two CPUs and each lane has to be identical you need two in the matching bank in the other lane. This means that yes you need to install DIMMs 4 at a time at minimum when using dual CPUs.

How do I query the DIMMS for their registered/unregistered/buffered status?  Server(s) are running XenServer, FWIW.

I'm not very familiar with Xen. You can try dmidecode --type memory. That will usually show the part number. You can use the part number to find details about the DIMM online. If that doesn't work then you can send me a private message with the service tag and I will check.

Thanks

There is probably a linux command similar to Windows' WMI that could query the memory information, but only 1GB and 2GB UDIMM's (Unbuffered/Unregistered) are supported in the T610, so it's more than likely that your 4GB DIMM's are RDIMM's (Registered), especially if they are the DIMM's that shipped from Dell.

Also keep in mind, that you must be running BIOS version 1.1.4 to use 16GB DIMM's.

I'm getting hung up on why it's pairs of chips within a bank, when a bank has 3 slots.  In any given bank, I put in a pair, and then there's a slot left over.  What's up with the leftover slot?

If it was that DIMMs needed to be installed in sets of 3, and each Bank must match (Lane 1, Bank 1 must be the same as Lane 2, Bank1), I'd get it.  But that's not what I'm reading.

dmidecode --type memory gives a type of DDR3 and Type Detail of Sychronous, but nothing re registered/unregistered/buffered.

The DIMMs came preinstalled from our reseller, so afaik, they shipped from Dell.

Is there a way to ask the BIOS it's version number, or does it need to be seen during POST?

OK, I think I get it now, but let me check-  Another way to say it is that of the 3 slots within a bank:

-Thou shalt not use only 1 slot (troubleshooting mode only)

-2 matching DIMMs are acceptable.

-3 matching DIMMs are also acceptable

And whatever you do within a bank, thou shalt replicate for the same bank on the other lane.

Yes?

Which boils down to if you want to add RAM, you're buying at either 4 DIMMs, or 6.

Looks like I'm OK with the BIOS minimum:

# dmidecode --type 0
# dmidecode 2.10
SMBIOS 2.6 present.

Handle 0x0000, DMI type 0, 24 bytes
BIOS Information
    Vendor: Dell Inc.
    Version: 2.1.9
    Release Date: 05/21/2010

and on the second server

dmidecode --type 0
# dmidecode 2.10
SMBIOS 2.6 present.

Handle 0x0000, DMI type 0, 24 bytes
BIOS Information
    Vendor: Dell Inc.
    Version: 6.0.7
    Release Date: 08/18/2011

Although I have to say the greatly different BIOS versions surprise me a bit.  They have different purchase dates, but that's a lot of revisions between 2.1.9 and 6.0.7.

Thanks for helping me understand the rules here, guys. Much appreciated.

I guess when your version numbers skip from 3.x to 6.x it's not quite as many revisions as it would look like at first glance. :)

OK, I think I get it now, but let me check-  Another way to say it is that of the 3 slots within a bank: -Thou shalt not use only 1 slot (troubleshooting mode only) -2 matching DIMMs are acceptable. -3 matching DIMMs are also acceptable And whatever you do within a bank, thou shalt replicate for the same bank on the other lane. Yes? Which boils down to if you want to add RAM, you're buying at either 4 DIMMs, or 6.

That sounds good to me.

6.3.0   - 08/15/2012
6.2.3   - 05/04/2012
6.1.0   - 11/07/2011
6.0.7   - 08/30/2011
3.0.0   - 02/04/2011
2.3.12 - 02/01/2011
2.2.11 - 01/05/2011
2.2.10 - 11/17/2010
2.1.15 - 09/08/2010
2.1.9   - 05/26/2010
2.0.13 - 04/07/2010
2.0.11 - 03/02/2010
1.3.6   - 11/04/2009
1.2.6   - 07/24/2009
1.1.4   - 05/15/2009
1.0.4   - 03/11/2009

It's a lot of updates, but it's been around a while too.  The big jumps usually represent significant changes to the system.