Windows 10: Help please 16gb ram but 100% when 8gb used , 16.0 GB 15.4 GB usable

I have 16gb ram 2x8 , fine in 3 years normal.But this happened several months ago. There is a strange thing, where the total RAM is 16GB but when you open a few applications the total is used 100%, but the information in the task manager is different. and I don't think I've used 16 RAM but it's 100% used.i think one of my ram broken so I've tried removing my RAM one by one and my RAM works fine.this is my screenshot in same time.i am sorry idk i cant upload img in herehttps://lh3.googleusercontent.com/drive-viewer/AK7aPaDa6jzXUM-rkDUgYUlcjFATyS5p8qel87KZgHlE7tewUEm30YR6xkVnGz1QBhjbp_JIw8cvbb

:)

 

Why 2.66 GB usable in 4 GB ram?

Thanks to everyone for their valuable suggestions. I guess the problem was with the OS.Because after increasing my ram from 4 gb to 8 gb still the usable memory was 2267 mb out of 8 gb, then I did a clean install of Windows 7.Now everything is fine and smooth, and usable memory is 7.9 gb out of 8 gb.

 

New 16GB RAM only 3.9 GB usable

The Asus specs on your motherboard: SABERTOOTH 990FX R2.0 | Motherboards | ASUS Global

states that the board supports maximum RAM of 32 GB ( 4 X 8 GB). It looks like it may not accept a 16 GB DIMM.

If you want to be conservative, only use RAM from the QVL (qualified vendors list):

SABERTOOTH 990FX R2.0 Memory / Device Support | Motherboards | ASUS Global

No DIMMs larger than 8GB are shown there. (There are some 2 X 8 and 4 X 8 sets.)

As an independent check, you can see what Crucial offers: RAM & SSD Upgrades | ASUS SABERTOOTH 990FX R2.0 | Crucial.com

Sorry about that.

 

16GB RAM only 8GB usable on Windows 10 x64

have 16GB of RAM installed on my computer, but only 8GB is usable. I am running Windows 10 x64. I have tried the following steps to fix this issue, but they have not worked:

1. I have updated the BIOS to the latest version.
   
2. I have tried reseating the RAM modules.
   
3. I have tried using different RAM modules.
   
4. I have tried run-MSConfig
   

I am still not able to use all 16GB of RAM. Any suggestions?

Thanks,

[Ahmed Hashem]