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

Spartan_029

Reputable
Nov 5, 2014
2
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4,510
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
 
Solution
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.

Spartan_029

Reputable
Nov 5, 2014
2
0
4,510


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.
 

jb6684

Distinguished
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.
 
Solution

kelsall784

Reputable
Oct 16, 2014
25
0
4,540
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...