Question Why is my pc only using 8gb of ram when i have 16gb

[hkon]

I recently upgraded my pc with some new ram i replaced the old ram and added 2 new sticks which is 16gb in total. But when i go into the bios aswell as task manager it displays 7.9gb of ram usable. I have tried to game games which is heavy on the ram. I then get a warning which says i have less than 10gb ram. My pc specs is: asus rog strix b350-f gamign amd ryzen 7 1700x, fury black 2x8gb 3200mhz. Thanks in advance for answers

 

[rgd1101]

try different ram slot?