single-ranked vs dual-ranked

Fred Skrotzki fskrotzki at
Fri Aug 4 11:27:25 CDT 2006

The server name you are attempting this in would help in this context.

4 gig dual rank dimms are available (you can order them for 1425, 2850,
2950).  It might be that the system you are attempting to put them into
just does not memory that large.

Each motherboard can only support so many rank selectors.  So once you
have used them up it will not see any more memory even if it is present.

There are 3 sets of dimms on the 1425 and 2850.  You can do mix and
match but the largest amount of memory that is possible is 4 x 4 gig
dual rank dims for a max of 16 gig.  I've not seen anybody whom has made
a single rank 4 gig Dimm.

Take a look at  for some
good info on memory...

-----Original Message-----
From: linux-poweredge-bounces at
[mailto:linux-poweredge-bounces at] On Behalf Of Jason Martens
Sent: Friday, August 04, 2006 11:10 AM
To: linux-poweredge at
Subject: single-ranked vs dual-ranked

Does anybody have a good description for the difference between
single-ranked dimms and dual-ranked dimms, especially what the maximum
memory is with dual-ranked dimms?  I have a system that has 4 2GB
dual-ranked dimms, and I want to upgrade it beyond 8GB.  My
understanding is that is impossible, unless I switch to all
single-ranked dimms, or purchase 4GB dual-ranked dimms (which don't seem
to be available).  Is that correct? 

Also, dmidecode seems to think that I have 6 2GB dimms installed, when I
really only have 4 (/proc/meminfo says 8GB total).

Jason Martens

Linux-PowerEdge mailing list
Linux-PowerEdge at
Please read the FAQ at

More information about the Linux-PowerEdge mailing list