[Okta Webinar] Learn how to a build a cloud-first strategyRegister Now

x
  • Status: Solved
  • Priority: Medium
  • Security: Public
  • Views: 3585
  • Last Modified:

What is the difference between dual ranked & single ranked DIMMs

I'm pricing a server, and need to know the difference ...aside from the fact that single ranked is $600 more.
0
cerminad
Asked:
cerminad
  • 3
  • 3
2 Solutions
 
CallandorCommented:
The dual-ranked DIMMs have a few features which the single-ranked ones do not.  See the second page of this document: http://www.valueram.com/news/pdf/MKF_676_MarketNews_oct.pdf
0
 
garycaseCommented:
See items #9 and #10 here:
http://www.corsairmicro.com/memory_basics/153707/index.html

Note that dual-ranked modules require an additional clock cycle to stabilize the chip select signal.

With registered (buffered) modules, either will be good, stable memory -- the only difference is in the possible feature sets, as noted in the article Callandor referenced.

Doesn't apply to your question (a server undoubtedly uses registered modules) -- but for anyone reading this in the future, with unbuffered modules the single banked modules have 1/2 of the loading on the memory controller (see #10 in my link) and will be more stable as a result.   That's why, by the way, many systems slow down the memory access speed (e.g. 400MHz memory runs at 333MHz) if you have 4 dual-bank modules installed.  (the degraded signal makes operation at high speed less reliable)
0
 
cerminadAuthor Commented:
I also should have noted this at first... The servers being spec'd out are a Dell 1850 & 6850.  1850 being used as a Citrix server & 6850 will be a web server.  Should I go with the single-ranked DIMMs?
0
Free learning courses: Active Directory Deep Dive

Get a firm grasp on your IT environment when you learn Active Directory best practices with Veeam! Watch all, or choose any amount, of this three-part webinar series to improve your skills. From the basics to virtualization and backup, we got you covered.

 
CallandorCommented:
I would think they would be fine, unless you specifically need the features noted for dual ranked ones.
0
 
garycaseCommented:
Callandor -- the extra features are provided by the single-ranked DIMMs :-)

Single-ranked DIMMs have a slight access time advantage;  use a bit less power; and have better ECC capabilities.   But as I noted above, the "normal" reason I suggest them is in unbuffered memory situations, where the reduced loading on the memory bus is an advantage -- but this is not a factor with buffered memory.   Bottom line:  it IS "better" memory => but either will work fine.
0
 
garycaseCommented:
... to more specifically answer your question, "Should I go with the single-ranked DIMMs?" ==> I would;  but be aware that it's an incremental advantage and you're paying a fair number of dollars for it.
0
 
CallandorCommented:
Gary, that's what I meant ... ;-)
0

Featured Post

Sign your company up to try the MB 660 headset now

Take control and stay focused in noisy open office environments with the MB 660. By reducing background noise, you can revitalize your office and improve concentration.

  • 3
  • 3
Tackle projects and never again get stuck behind a technical roadblock.
Join Now