SaberTooth x79 Ram unrecognized/capped

[shards]

Hello,

I've just upgraded to sabertoothx79 and intel i74820 from my old AMD system.

I have 3 sticks of 12gb RAM each but in the bios they get seen as 4 gb each. its the kingston KHX1600C9D3K3/12GX

I also have one stick of 8gb which is the KHX1600C9D3X2K2/8GX this also get recognized as 4gb max in the bios.

I tried them individually, on different channels, in couple, the 8gb alone and the 12gb alone etc. with every combination they always show the same amount regardless.

I know its not recommended to mix them but now i put them all in and i got 16gb but still, not sure if its because of compatibility or there's something wrong with the mobo?
I'm running everything at stock,I'm sure the ram works as I was using them all in my previous rig.
I'm sure I'm using the right channels as well, cpuid Says "Quad" in the channels# section of the memory so it is using all of them. I'm in 64bits window 7.


any info would be very appreciated!

 

[redduc900]

KHX1600C9D3K3/12GX is a 12GB kit, which consists of 3 x 4GB modules. The KHX1600C9D3X2K2/8GX is a 2 x 4GB kit, of which you have 1 x 4GB module.

 

[shards]

oh..lol I'm a noob sorry. I got those ages ago and came across the box but was misled by the label.. thanks a lot!

now I found the other module of the 8gb kit, would it be bad to add it and have 5 modules total?

 

[redduc900]

You'd lose quad-channel mode, since it requires four (or a multiple of four) modules identical in capacity and speed installed in quad-channel slots. You'd be better off w/ 4 x 4GB modules installed in a quad-channel config., than w/ 5 x 4GB installed in a dual-channel / flex-mode config.

 

[shards]

i'm not sure how the channel "pairing" works but wouldn't it keep the quad channel and add a single channel on top?

tried a maxxmem test before and after, i seem to be getting pretty much the same results.