GA 78LMT USB3 Memory problems

[Rabbit-Runner]

I purchased a new mobo, cpu, and memory (2x4=8 GB). I have a 1 TB hard drive, split into two equal partitions. There are two operating systems installed, one on each partition; Windows 7 Pro, and Windows Server 2012. Both are 64 bit OS's.

The operating systems installed without any problem. During the boot, I can select either OS.

The 'system' information on both OS's show that they are the 64 bit versions.

However, here is the problem. Both OS's show that 8 GB of memory is installed, but only 3.75 is available.

I understand that part of the memory is used for the onboard video. I have adjusted that within the BIOS and the available memory changes from 3.48 to 3.75. All depending upon where it is set, the available memory will adjust slightly, based upon how much memory is allocated for the video.

The memory is two sticks of Kingston HyperX FURY 4GB 1600MHz DDR3. I have tried placing the sticks in different slots; 1-3, 2-4, 1-2, 3-4. The only combinations that work are 1-3 and 2-4. The others give only a blank screen.

From all of my testing, the problem appears to be that the Mobo thinks the OS's are 32 bit, and only releasing half of the memory because of that.

I've tried adjusting the settings in MSCONFIG > BOOT > Advanced Options. None of the setting makes any difference.

Anyone else experienced this problem?

Anyone have a solution? I would appreciate any help. Thanks in advance.

 

[clutchc]

What does cpu-z show, dual channel or single channel? Does it show both sticks as it should?

 

[Rabbit-Runner]

CPU-Z shows sngle channel.

Type DDR3

Size 8 GBytes

NB Frequncy 2008.5 MHz

CPU is 6 core

 

[clutchc]

the matched pairs need to be in slots DDR3-2 and -1 or DDR3-4 and -3 for dual channel mode. You are in single channel mode because they are in same channels. Page 11 in the MB manual.
But if they fail in the correct slots, it would appear the board is defective. And it doesn't explain what Windows doesn't use all 8 GB, unless one of the slots you are in is also bad.

 

[spooky2th]

What is the exact model of the memory kit? And if CPUZ shows single channel, maybe you are installing in the wrong slots?

What is the model & revision of your MB?

 

[Rabbit-Runner]

I tried changing the memory to the different memory slots. When I try DDR3-1 and DDR3-3 OR DDR3-2 and DDR3-4, the memory shows up as single channel. During the POST, when booting, only 4 GB of memory shows. However in Windows, it still says 8 GB installed, 3.75 Available.

When I try the sticks in DDR3-1 and DDR3-2 OR DDR3-3 and DDR3-4, then no post and no video.

Board info: (via CPU-Z)
GA 78LMT USB3 x.x
Date 04/23/2013
Version: FA

 

[clutchc]

I tried changing the memory to the different memory slots. When I try DDR3-1 and DDR3-3 OR DDR3-2 and DDR3-4, the memory shows up as single channel. During the POST, when booting, only 4 GB of memory shows. However in Windows, it still says 8 GB installed, 3.75 Available.

When I try the sticks in DDR3-1 and DDR3-2 OR DDR3-3 and DDR3-4, then no post and no video.

Board info: (via CPU-Z)
GA 78LMT USB3 x.x
Date 04/23/2013
Version: FA

Then I would have to assume the board is defective. You might get lucky and bring them back to life with a BIOS reset. Or by updating the BIOS to the latest version. But if the board is new, I'd RMA it while you still can.

Have you checked each stick of memory INDIVIDUALLY with memtest for at least one full pass to be sure they are OK?
http://www.memtest.org/