rx8640 - Memory configuration

[Gene Laoyan]

We have an rx8640 and want to upgrade the RAM. Currently it is populated with 8 2GB sticks.
My question is, can we populate the available slots with 4GB sticks without voiding any warranty or anyting, basically mix & match sizes. These will be HP sticks that we purchase.
Will there be be any performance hits?

Thanks

[Steven E. Protter]

Shalom,

There will be no performance hits adding memory that is certified for the rx8640 to empty memory slots.

Note that they have to be added in pairs.

See the documentation in http://docs.hp.com for this system for details on memory and upgrades.

SEP

[Gene Laoyan]

Could you confirem that 64GB is the MAX memory that can be installed?

Thanks

[Pete Randall]

According to my trusty "Hardware @ a Glance" chart, the max for the 8640 is 256GB.


Pete

[Pete Randall]

I should add that, obviously, 256GB in 32 slots means that you're using something larger than 4GB sticks - roughly 8GB, I would guess.

And you have to add the larger sticks in the lowest numbered slots, by the way.


Pete

[Sandman!]

Actually it is 512GB. See below:

http://docs.hp.com/en/AB297-9007C/ch01s01.html#d0e990

[Gene Laoyan]

OK, now I am confused. In a previous post: http://forums1.itrc.hp.com/service/forums/questionanswer.do?threadId=1151317 I ran a command that shows there are 32 slots and 8 are used. In the web page I was directed to it shows there are 16 slots total: see figure 1-9: http://docs.hp.com/en/AB297-9007C/ch01s01.html#d0e990

Which is it? We need to buy more RAM but need to know the density to properly populate all 4 nPars to at least 32GB of RAM. Currently there's 16GB.

Thanks everyone.

[Pete Randall]

It definitively states 256GB on these specs:

http://h20341.www2.hp.com/integrity/cache/340168-0-0-0-121.html


Pete

[Sandman!]

Is this server an nPar? You may have two cell boards in the machine which are coupled together to form a single nPar. Each cell board has 16 DIMMs which can be populated by 1 2 4 or 8 GB DIMMs.

~hope it helps

[Gene Laoyan]

Yes it is an nPar. We want to upgrade memory on all 4 nPars to at least 32GB each. Will we need to purchase 8 2GB sticks for each nPar or 4 4GB sticks for each nPar?

[Duncan Edmonstone · Accepted solution]

Gene,

I'm willing to be proven wrong but I think you have hit on an issue which I've seen before with STM when looking at some memory configurations.

The cell board in the rx8640 does indeed only take 16 DIMMs, not 32 and they are laoded in pairs. But STM shows up to 32 DIMMs per cell board because a cell board on a Superdome has this many.

So I would open a case with HP and confirm you are getting incorrect info out of STM, because for me STM shouldn't be telling you about slots 8A to FB as they don't exist on the rx8640.

I'm happy to stand corrected if I've missed something!

HTH

Duncan

[Gene Laoyan]

Duncan, you are correct. There are 16 DIMM slots 8 of them are populated with 2GB modules. I just got off the phone with HP and they confirmed this. So we will be populating 4 available slots with 4GB module for each nPar.

[Gene Laoyan]

Thanks a bunch everyone!