One of the channels for dual channel mode is disabled

[fredjpreston]

I'm trying to install 4 RAM sticks on a Gigabyte P55 UD3 mobo but I'm having problems with that.

As you can see in the picture attached, the 2 rams that are installed in slots 3 and 4 are disabled. I switched their places and still the result was the same.

I can only get 2 DIMM slots to work I don't know why.

Though the mobo recognizes the rams and gives me a total of 12 GB of RAM, it still shows that 6 or 8 GB of the total RAM (depending on the placement of the sticks) is "Hardware Reserved"!
I have all the installed sticks on the mainboard info list.

2x 2 GB and 2x 4 GB
One of each is working and the total is 6 GB of RAM available.

On the "Enabled Slots" 2 of the slots are disabled and there is only a " - " in their info column.

I had It working perfectly fine until I water cooled my CPU but I dont think that this could be related
The pc also will not boot in I use certain arrangements of the ram

 

[RememberThe5th]

You need to do A1-B1-A2-B2
Match A1 and A2 with 2x2 (vice versa) and B1 and B2 with 2x4GB.

 

[fredjpreston]

You need to do A1-B1-A2-B2
Match A1 and A2 with 2x2 (vice versa) and B1 and B2 with 2x4GB.

When I do this though the pc doesn't boot at all, I cant even get into the bios