Windows 7 Professional not using all RAM - 24GB Installed (16 Usable)

[Spartan_029]

Hi all,

I've been looking all over and all I get is the same answers, when someone has more than 16GB RAM, and windows on sees 16, it seems that there are 2 answers:

1: They are using Home Premium, not Pro/Ultimate
- I am using Pro
2: The Hardware sees all RAM, but windows only shows 16GB total installed
- Windows shows: Installed Memory (RAM): 24.0 GB (16.0 GB Usable)

Troubleshooting steps already performed:
- Re-seated the RAM
- Tested each stick, in each slot individually
- Checked MSCONFIG and confirmed max memory was unchecked
- Confirmed all RAM is seen in the BIOS menu
- Reset the BIOS
- Sacrificed 2 virgin goats

I'm out of ideas, any thoughts from the general public?

Relevant Hardware Specs:

MoBo: Gigabyte X58A-UD3R
RAM: 24GB (6x4GB) Kingston HyperX DDR3

Screenshot of Properties/msconfig/cpu-z tabs
http://imgur.com/YuS7FLm

 

[Ironsounds]

Hello... Try these suggestions since you have a 64 bit OS B ) http://www.sevenforums.com/tutorials/66482-memory-set-maximum-amount-used-windows.html Do you have Ram allocated for your CPU/IGT in your BIOs?

 

[ahnilated]

Have you run memtest86 on the ram while all 4 chips are installed?

 

[Spartan_029]

Have you run memtest86 on the ram while all 4 chips are installed?

shoot, one thing I have not tried.

I'm moving this weekend, and all my boot media is packed away I'll try this next week and get back to you.

 

[Tradesman1]

Might try raising the DRAM and/or MC voltage a bit, try about + 0.05

 

[jb6684]

Your trouble may be same as mine; I'm on an x58 platform too (ASUS MB). I run Win 7 Pro. I run 6 x 2 Gb. I often have system detects only 8 Gb. When I run CPU-Z, it shows all 12 Gb.

Solution: I had to run RAM at 1066Mhz (even thou RAM is 1600Mhz RAM). And, bumped up voltage to 1.65V, it's spec'd to run at 1.6V.
Reason: x58 platform does not support running more than 3 sticks of RAM above 1066Mhz. Yup, you can OC 3 sticks to 1600Mhz n beyond but NOT 6 sticks.

 

[kelsall784]

i had the same problem and i found that it was in the system config
worth a shot @ having a look. search msconfg in start tab go to boot tab // advanced options// and make sure number of processors and maximum memory boxes are both unchecked and reboot...