Mixing PC3-10600 with PC3-12800 memory in my proliant servers

[ArielZusya]

I've got the following three servers (all HP Proliant with single processors):

DL380 G7 with nine 2048mb x 1333Mhz RDIMMs (PC3-10600) for a total of 18Gb

DL360 G7 with six 2048mb x 1333Mhz RDIMMs (PC3-10600) for a total of 12Gb

DL360e G8 with two 8192mb x 1333Mhz RDIMMs (PC3-10600) for a total of 16Gb

I've been asked to increase the memory on the servers. I was thinking about adding 24Gb (an 8 and a 16) to each. I would take two of the RDIMMs out of the DL380 G7 to make room for the new RDIMMs. This would give me 38Gb in that machine. I would then have 36Gb in the DL360 G7. Finally I would use the two RDIMMs I removed from the DL380 G7 and use those along with the additional memory in the DL360e G8 for a total of 42Gb. I believe the plan is workable so far, but if I'm incorrect, please let me know. (Incidentally, the systems all are using ECC at 1.35V. Just want all the info out there.)

I've got HP branded memory in the machines now but I'd prefer not to spend the money on HP memory for this upgrade (since it is roughly twice the price). Crucial has 8Gb PC3-12800 RDIMMs for $100 and 16Gb PC3-12800 RDIMMs for $173. Crucial doesn't have PC3-10600 RDIMMs in 8 or 16. If I go with something like Edge, I can get 10600 16Gb at CDW for $192 (though these are marked as "call" whereas the ones that are available in 1-3 days are $280 which is inching closer to HP branded memory) and 8Gb for $105.

I assume that if I stick PC3-12800 RDIMMs in with my 10600 they will be downsampled to 1333Mhz. Am I correct? Is downsampling a bad thing? If it isn't a bad thing is it better to go that route and save the cash or should I go the Edge route and stick with all 10600 memory?

[suresh_babu]

Hi,

I see that you are trying to upgrade the DIMMs on 3 different model of servers  DL380 G7, DL360 G7 & DL360e Gen8

I would like to address the query based on the server models

a) DL380 G7 with nine 2048mb x 1333Mhz RDIMMs (PC3-10600) for a total of 18Gb

MEMORY OPTIONS SUPPORTED:-

---------------------------------

PC3-10600 RDIMMs

PC3-8500 RDIMMs

NOTE:  if you install 1x 1066MHz DIMM in channel 1 and 1x 1333MHz DIMM in channel 2, you still run at 1066MHz

MEMORY UPGRADE OPTIONS:-

------------------------------

HP 8GB (1x8GB) Dual Rank x4 PC3-10600 (DDR3-1333) Registered CAS-9 Memory Kit --                         500662-B21

HP 8GB (1x8GB) Dual Rank x4 PC3L-10600 (DDR3-1333) Registered CAS-9 Low Power Memory Kit --604506-B21

HP 16GB (1x16GB) Quad Rank x4 PC3-8500 (DDR3-1066) Registered CAS-7 Memory Kit ---                   500666-B21

HP 16GB (1x16GB) Dual Rank x4 PC3L-10600 (DDR3-1333) Registered CAS-9 LP Memory Kit ---          627812-B21

MEMORY POPULATION GUIDELINES: (Refer Pg. 42)

---------------------------------------------------------

http://www8.hp.com/h20195/v2/GetDocument.aspx?docname=c04199811

For detailed memory  configuration rules and guidelines, please use the Online DDR3 Memory Configuration Tool:

www.hp.com/go/ddr3memory-configurator

b) DL360 G7 with six 2048mb x 1333Mhz RDIMMs (PC3-10600) for a total of 12Gb

MEMORY OPTIONS SUPPORTED:-

---------------------------------

PC3-10600 RDIMMs

PC3-8500 RDIMMs

NOTE:  if you install 1x 1066MHz DIMM in channel 1 and 1x 1333MHz DIMM in channel 2, you still run at 1066MHz

MEMORY UPGRADE OPTIONS:-

------------------------------

HP 8GB (1x8GB) Dual Rank x4 PC3-10600 (DDR3-1333) Registered CAS-9 Memory Kit  --                            500662-B21
HP 8GB (1x8GB) Dual Rank x4 PC3L-10600 (DDR3-1333) Registered CAS-9 Low Power Memory Kit         604506-B21
HP 16GB (1x16GB) Quad Rank x4 PC3-8500 (DDR3-1066) Registered CAS-7 Memory Kit --                         500666-B21
HP 16GB (1x16GB) Dual Rank x4 PC3L-10600 (DDR3-1333) Registered CAS-9 LP Memory Kit  --                 627812-B21

MEMORY POPULATION GUIDELINES: (Refer Pg. 40)

---------------------------------------------------------

http://www8.hp.com/h20195/v2/GetDocument.aspx?docname=c04284501

For detailed memory  configuration rules and guidelines, please use the Online DDR3 Memory Configuration Tool:

www.hp.com/go/ddr3memory-configurator

c) DL360e G8 with two 8192mb x 1333Mhz RDIMMs (PC3-10600) for a total of 16Gb

MEMORY OPTIONS SUPPORTED

--------------------------------

PC3-12800 RDIMM

PC3-10600 RDIMMs

PC3-8500 RDIMMs

MEMORY UPGRADE OPTIONS:-  (pls refer pg. 27 for huge list of upgrade options)

------------------------------

http://www8.hp.com/h20195/v2/GetDocument.aspx?docname=c04123219

MEMORY POPULATION GUIDELINES: (Refer Pg. 50)

---------------------------------------------------------

Depending upon the processors installed

http://www8.hp.com/h20195/v2/GetDocument.aspx?docname=c04123219

VERY  IMPORTANT POINTS TO BE TAKEN INTO CONSIDERATION WHILE UPGRADING DIMMs

----------------------------------------------------------------------------------------------

- HP memory from previous generation servers (eg. g7 server)  is NOT compatible with the DL360e Gen8 Server.

Certain HP SmartMemory features such as memory authentication and enhanced performance may not be supported.

 - RDIMMs operating at either 1.35V or 1.5V may be mixed in any order, but the system will power them at the higher voltage

 - DIMMs of different speeds may be mixed in any order; the server will select a common optimal speed

 - HP always recommends HP certified DIMMs to be installed on servers for better performance and stability.

To realize the performance memory capabilities listed in this document, HP SmartMemory is required.  For additional information, please see the HP SmartMemory QuickSpecs at:

http://h18000.www1.hp.com/products/quickspecs/14225_div/14225_div.html

I understand cost plays a major part while going for upgradation,  however installing HP certified DIMMs is highly recommended as this would be part of  the compatible list of HP certified hardware and most important hardware replacement under warranty becomes easier.

Regarding the downsampling of the speed,yes you are absolutely correct.  When  PC3 12800 (1600MHz) installed with PC3 10600 (1333 Mhz) , it works at 1333Mhz. Moreover downsampling of speed does not cause a major harm.

Hope the above information helps. Please revert for any clarifications.

I work for HP

A quick resolution to technical issues for your HP Enterprise products is just a click http://www.hp.com/go/hpsc" HP Support Center Knowledge-base "http://h30499.www3.hp.com/t5/Announcements/Self-Help-Just-a-Click-Away/td-p/6737641"

[MM_Z]

Best to follow optimal performance guidelines.

All servers are 3 memory channel capable. So it makes sense to populate slots in multiples of 3 for best memory performance.

DL380 G7

Having 9 RDIMMs in single CPU DL380 G7 is not the greatest idea, since it runs at 800MHz only (3DPC = speed penalty). My suggestion is to take out 6 pcs 2GB RDIMMs and get 3x 8GB RDIMMs for total of 30GB of memory.  It will run at full speed (1333MHz)** at 1.5V instead of 800MHz right now. If speed is not concern, you can keep additional 3 pcs of existing 2GB RDIMMs for total 36GB running at 800MHz.

DL360 G7

My suggestion is to take out 3 pcs 2GB RDIMMs and get 3x 8GB RDIMMs for total of 30GB of memory.  It will run at full speed (1333MHz)** at 1.5V. If speed is not concern, you can keep additional 3 pcs of existing 2GB RDIMMs for total 36GB running at 800MHz.

DL380e Gen8

get 1 more 8GB RDIMM and use 3 pcs 2GB RDIMMs* (if not used) from DL380/DL360 for total of 30GB of memory.

U can only use 6 memory slots if 1 CPU is installed ...

*be advised that G7 memory is not HP supported in Gen8 servers, but will work

EDIT (for clarification): **presuming installed CPU and memory is 1333MHz capable

Regarding memory brand - get second hand original HP, if servers are still under HP warranty. IF not,  just buy either refurbished HP or new Crucial, whatever is cheaper.