[SOLVED] Windows 10 only using 7.9GB of 16 available

[tarnyost]

Hey guys
Having some issues with Windows 10 not using half of my RAM. I've tried several solutions I've seen here and haven't been able to figure it out. The odd hing is that it worked until I replaced a GFX card (an old one I've used as a fallback before)

I'm usually pretty savvy troubleshooting my own PC issues but this has me stumped.

Hardware
Mobo: Asus M5A99FX Pro 2.0
CPU: AMD 8350 FX
Memory: 2x8GB Kingston HyperX DD3

Steps Taken
1. Reseat both chips and tested both slots - Both chips work in either slot on their own, so it's neither the slots nor the chip. (I hope) RAM is in slots #1 and #3.
2. Checked BIOS - I've left it at optimal settings but on the Main Bios page it only says there is 8GB, but on the Memory page it shows both chips are there. BIOS is up to date with version 2501
3. Memtest - no errors
4. I've probably checked half a dozen Windows tweaks with memory settings and nothing has changed it.

'resmon' - shows this
https://www.screencast.com/t/CnBWCHwxNcc

My GFX card died recently and I added an old one until my replacement arrives ( I live out of the US so everything takes time to get here). I am wondering if somehow this might have caused anything but I can't find any info on why this might be the issue.

Any help would be awesome! A solution earns you a beer down here in Costa Rica! 😀

Thanks!

 

[Calvin7]

Memory: 2x8GB Kingston HyperX DD3

Memory part number and/or link to it?

 

[tarnyost]

The memory part number is HX318C10FBK2/16

 

[tarnyost]

I was able to fix it by putting the RAM in slots 2 and 4, windows now shows 16GB. Odd. Will using the other 2 slots affect anything? I've always used 1 and 3

 

[howtobeironic]

No, basically odd numbered slots and even numbered slots are channeled into each other (means 1-3 and 2-4 are channels) which if you slot in rams to both, they'll be faster than a single stick equivalent (example, 2*8 GB sticks will be working faster than 1*16 GB stick of the same frequency)
Using all four, they'll boost each other two by two, however you'll be sticking to the frequency of the lowest stick, if different sticks. You'll need two things to know if you motherboard can:

1)four of the same sticks.
2)motherboard has to support quad channel for your stick model.