Windows 7 system only recognizing 16GB out of 32GB newly installed RAM

swmonty

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Aug 3, 2013
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Hi all,

I'm having some difficulties with a newly built Windows 7 system, particularly with the RAM. The problem is I have installed 32GB of memory (8 x 4GB), but Windows is only recognizing 16GB.

My motherboard is an ASUS P9X79 WS. I have verified that this mobo supports well over 32GB of RAM, and I have updated the BIOS to the most recent update with the ASUS update utility.

I am using Windows 7 Professional 64 bit. I understand that some versions of Win7 put a cap on memory, but I don't believe that is the case here.

My memory is G.Skill Ripjaws Z Series 240-Pin DDR3 1600. All sticks are the same and are not mixed with other brands. There are 8 total sticks @ 4 GB each.

I'm using the CPU-Z utility to examine my system. That program reports to me that 32GB of memory is indeed installed. However, when I go into my UEFI BIOS interface, I am seeing that the entire right side (C1,C2,D1,D2 slots) is listed in yellow as "abnormal". The left side (A1,A2,B1,B2) is all listed as OK.

If anyone has any suggestions as to a possible solution, I'd be greatly appreciative. I'm really hoping that there's a fix to this that doesn't involve tearing the machine apart and RMA'ing the mobo for faulty slots.

Thanks,
Sean
 

Tradesman1

Legenda in Aeternum
Since it's Win7 Pro 64, yes it should support it... First check in MSCONFIG to see if limited by Win

Start > type MSCONFIG in search window > Enter > Boot > Advanced make sure max mem is unchecked

Next thing can check if that's not it, Is this from 1 single package of DRAM, or did the sticks come in 2 or more packages - if so, it's never a good idea to mix sets, it can be problematic, even if the same exact model...which is why they sell in multiple stick sets - all the sticks in a set are tested to play nice with each other...with tolerances so tight if not tested together - there's a good chance they won't play. Also if multiple sets, XMP doesn't work - the programming is by the set, and in the advanced timings, which you don't see on a package, things like the tRFC go up the more sticks you have 16GB might need a tRFC of 208 and a 32GB set might need 314..

Anyway, if you can provide the actual model # of the DRAM (and how many packages involved along with your current base DRAM timings, voltage, MC (memory controller) voltage (think VTT on your mobo) and the VCCSA voltage, we can prob get these sticks to work

 

swmonty

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Aug 3, 2013
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Hi Tradesman,

I have checked msconfig, and it is not being limited by Windows.

The 8 sticks of RAM were all purchased at the same time as a set from Newegg. The model is F3-12800CL9Q2-32GBZL.
Here is the exact item that was bought:
http://www.newegg.com/Product/Product.aspx?Item=N82E16820231498

Since I'm not overly experienced with manual timing of RAM, my current settings are pretty much the same as the specs listed on the Newegg page:

DDR3 1600 (PC3 12800)
Timing 9-9-9-24
Cas Latency 9
Voltage 1.5V
 

Tradesman1

Legenda in Aeternum
Ok then, hopefully this will be painless, first do you have the latest BIOS? if not, go ahead and get it.

Next, reseat all the sticks, and then go into BIOS, go to the advanced or tweaker page and ENABLE XMP, then select Profile 1, then set DRAM voltage to 1.55, VTT to 1.2 and VCCSA voltage to 1.16 and give it a try
 

swmonty

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Aug 3, 2013
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I have tested these steps, and Windows system properties is still reporting 16 GB -- so no change.

I certainly don't want to jump to drastic conclusions, but potentially concerning to me is a test I just did. As I mentioned in the original post, it almost seems like the left slots (AB) are fine, while the entire right side (CD) is dead. I removed all 4 sticks from the "good" side, leaving only the 4 in the "dead" or "abnormal" side. The system would not even boot up with that configuration. Does this sound like a faulty mobo?

If it helps, this is what I currently see with all 8 sticks seated:
abnormal.jpg
 

Tradesman1

Legenda in Aeternum
I had my fingers crossed also, but that sort of narrows things to mobo or CPU....might want to pull the CPU and check that there's no debris or thermal compound in the socket or on the bottom of the CPU and carefully check the socket for bent/broken pins - if nothing apparent, then put back together and try one more time, no joy and I'd RMA both as defective, unless you want to take it to a shop and see if they can narrow it to a single component
 

jeorge_kabbi

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Oct 11, 2013
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i had the same issue today. my motherboard has 8 ram slots (4 channels) and i have 4X8GB ram set. it turns out that i installed 2 sticks of RAM in channel A and 2 sticks in channel B and left channel C and D empty. in this configuration the BIOS detect 32 GB but win7 pro detect only 16GB.
but if i installed the ram sticks proberly ( 8GB in each channel) both win7 pro and BIOS detect 32 GB of ram!!
solved :)
 

wesley77

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Nov 30, 2013
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i had the same problem, 4gig was reserved for hardware. In the bios is said only 4g was usable to i switched the 4g stick with a new one wich costs a little more and it workes.

p.s. i have totel of 8g (2x2 1x4)
some mobos don't reconise your newly places dimms
 

erg208

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Oct 17, 2012
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First
You need to check if the RAM you installed is classified "unbuffered" and "Non-ECC"
This is what your motherboard ASUS P9X79 WS requires.
If it is... Then go to the bios and make sure that ECC is turned OFF.


Second
Your motherboard supports Intel Socket 2011 processor.
Go to Intel.com
Check what type of processor you have.
Under Memory Specifications look for Max Memory Size supported.

For example the
Intel Core i7-990X Processor Extreme Edition 3.46 GHz
will support a Max Memory Size of 24GB DDR3-1066

I hope this helps.




 

jlrietman

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Mar 14, 2014
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Had the same problem, CPU-Z showed 32G but Windows properties only showed 15.9. All memory slots matched and filled with same RAM. Solution was to unplug the computer and clear the CMOS by pulling the CMOS battery for 5-10 seconds.
 

Brandonriess8

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Jan 14, 2014
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[strike][/strike]you revealed something important in your last post. You said you were using 8 sticks. This means your motherboard has 8 slots. If I'm correct, each of these slots is either one color or another. That means that it consists of 2 channels; channel A and channel B. Most likely, channel B is not activated I'm the BIOS. Just a guess, but that's probably why only half your RAM is working.