Motherboard has 16 gigs installed but only recognizes 8gigs

[monkeylt]

Hello,

I built a pc about 2 years back, This is my first build and im not to experienced so forgive me in advance. The pc specs are below:
motherboard - sabertooth 990fx r2.0
CPU - I don't recall at the moment but will update
memory - 2 x 4gbs of G.skill Ram 1600MHZ installed in Slot 1 and 3
video card - Geforce gtx 960
Windows is 64 bit Windows 7

The Issue - I upgraded memory on the motherboard with 2sticks of 8gb G.skill 1866mhz in Slots 1(A1) and 3(B1) and in the BIOS it only shows 8 gigs of ram

What I have Tried-
-I tried switching the Ram from Slots 1 and 3 to 2 and 4 (A2 and B2 respectively) - No luck
-I went into tools and in tools the motheboard sees the Ram is in Slot 2 and 4 and that they are both 8 gig sticks and it sees the same if I switch back to 1 and 3.
I was also having an issue with getting them to run at 1866 but found XMP profile 1 and turned that on. So now my the motherboard is seeing one 8gb stick at 1866mhz in the main bios screen but wont use both.
- I reinstalled my 2 4gb g.skill ram sticks and I have the same issue( I think Ive been having this issue since the build) and the main bios screen only sees one 4 gb stick but under the tools menu in BIOS it sees each stick at its specification no matter which slot I moved them too.
- When Im on windows in Task manager or msconfig Windows sees 16gbs however its showing 8 gbs reserved.
-The new 2x8gb sticks are dual channel as well and A2 and B2 are the recomended slots and thats where they are now.

Thats All the information I have a the moment but Im hoping someone can help. Forgive my ignorance if I ask a dumb question. I dont think the Ram sticks are bad since they work in all slots but correct me if Im wrong

 

[Lutfij]

Have you made sure your motherboard BIOS is up to date? If you're running a dual channel 2x8GB kit then the rams should be populating slots A2 and B2 as stated in your motherboard manual.

 

[indsup]

Sounds like a compatibility issue to me. Try one stick at a time and see if the bios shows each at the same speed and capacity. If it does it shouldn't be that they are bad but it could be a compatibility issue. Did you look at the compatibility chart? Return them and order one of the kits listed on the list. That may be your only option to get them working correctly.

 

[maestro0428]

Yeah, you have two different speeds of memory there. Did you go into the BIOS and set the memory to 1600 (the lowest speed kit you have)?

 

[monkeylt]

I havent checked in the motherboard bios is up to date, I will thanks! and they are in A2 and B2.

when i tried just one stick, the PC wouldnt boot. However when I did try each stick in each slot the Tools option in the bios indicated they were 8 gb sticks of ram that could run at 1866mhz. I did look at the compatability chart and the particular numbers wasnt on the list but G.Skill ram in several in gb was, I thought theyd run since they ran all the other g.skill ram

And as for the speed, when doing research I found the board support 1866 Mhz so since I was already doing the upgrade I went ahead and got he 1866mhz over the 1600mhz, I did try setting the memory lower earlier on and went down to 1600 and 1333 and neither would show the second stick

So I will update the BIOS and if not I guess return them, Thank you for the help