Asus P6X58D-E ram issues

[le0nftw]

First post here guys but been a big fan of the youtube channel for a while now

 

I Just wondered if anybody could shed some light on a problem I'm getting with my own computer

 

My components

 

Intel i7 950 d0

P6X58D-E

Corsair XMS3 Triple 1600mhz C9 (2x6GB kits) (CMX6GX3M3A1600C9)

Windows 7 Ultimate 64bit

 

When I built the computer a couple of years ago now I originally only had the 1x3x2GB kit (6GB total), A short while after building I noticed the *matching* ram kits were on special offer and thought I'd try future proof myself for a small cost but never bothered fitting the memory until recently as I upgraded my graphics card to a Nvidia 770

 

After fitting the extra kit of memory I had lying around and my graphics card first time booting the system up I noticed it tried to power up and restarted itself before it would post anything on the monitor. Thought this was weird, took out the extra ram and It booted first time fine, so I knew the 770 gpu was ok. I then decided to swop the ram which has been in the system since I built it a while ago with the later ram and it booted fine, so I was thinking both my ram kits are fine hopefully and it could of been a bios update time maybe

 

After installing all the ram back into the board and finding the bios update off the asus site I noticed that the bios was only showing 8GB of memory and windows was only showing 8GB too. CPU-Z does show every slot has memory populated in it and shows 12GB

 

Just a quick question if anybody else has ever had this issue and I'm pretty sure the failing to boot first time and only showing 8gb are connected?

 

I'm running the memory in XMP 1600, I've looked at the corsair website and i'm pretty sure the timing of the ram is all ok 9-9-9-24, Hopefully I'm making a silly mistake somewhere along the lines

 

Thanks to anybody who takes the time to read this post