16gb RAM installed but only half is usable. Please help.

[alcatraz_ege]

This is my cousins pc. We tried everything we could in msconfig, regedit, paging. When we go into the bios, the motherboard recognizes both dimms but it says that 8gb physical memory is available. Similar to this, when we insepct system info windows shows that the loaded total physical memory is 16gb but then it says that total physical memory is 7.95gb and shows only 5.89gb of that as useable.

Specs: CPU: Ryzen 5 1600

Ram: hyper x fury 8gb DDR4 2667mhz (x2)

Motherboard: MSI A320m pro-5

edit: just to be sure we put his ram sticks into my motherboard and they worked just fine. 16gb physical, 16gb usable etc..

Edited December 4, 2020 by alcatraz_ege
added more info

[Ryzen-9]

It sounds like it's windows but just to be sure you could try each stick in a known working slot and make sure that it's able to use 8 gigs when only one stick is present.

[alcatraz_ege]

1 hour ago, Ryzen-9 said:

It sounds like it's windows but just to be sure you could try each stick in a known working slot and make sure that it's able to use 8 gigs when only one stick is present.

As I said we can see both dimms in the bios so I don't think the slots are faulty if that is what's on your mind, but still we'll try this right now and get back. Thank you.

[alcatraz_ege]

1 hour ago, alcatraz_ege said:

As I said we can see both dimms in the bios so I don't think the slots are faulty if that is what's on your mind, but still we'll try this right now and get back. Thank you.

 

1 hour ago, Ryzen-9 said:

It sounds like it's windows but just to be sure you could try each stick in a known working slot and make sure that it's able to use 8 gigs when only one stick is present.

tried both slots, both show 8gb physical and 8gb usable with single sticks.

[Ryzen-9]

You could try clearing CMOS and if you want you can update the bios to the newest version.

[Tetanus]

I had the exact same issue on a 1600X and tried everything to figure it out. Drove me absolutely mad. 16 gigs in bios, 8 in windows. 
 

Ended up pulling the cpu to inspect the pins and found a tiny piece of plastic. It was very small, maybe half the width of a hair and 1-2 mm long. It was lodged in between the pins. 
 

Not saying this is your issue, but try to reseat the cpu. 
 

Here’s my thread on the issue.
 

- T

Edited December 4, 2020 by Tetanus
Added link.