Gigabyte Z68XP-UD3P - Works With 12GB Ram, Not 16GB

[Tenatious]

Hey,

So I've got a bit of a conundrum that maybe someone can shed some light on! Basically, I initially ordered 8GB Crucial Ballistix Tactical Tracer RAM with my new build... seemed to run in to some problems with having both sticks installed.

So, I bought 8GB Corsair Vengeance and this works absolutely fine. Now I've got an RMA number for the crucial but thought I'd check it one last time so I don't look an idiot and end up having to pay because they don't see it as faulty.

Basically,
I have the 8GB Corsair in, and also one stick (4GB) of the crucial and this shows as the correct 12GB on boot and also runs Memtest fine. I've run it alternating the two sticks so I don't think that is the issue. The issue seems to occur when I try and put both sticks of the crucial in, either on there own or with the corsair. The computer just will not turn on. The fans boot for about a second and then it turns off and this will repeat until I remove one of the sticks of crucial.

My current BIOS settings are as follows:

Extreme Memory Profile: Profile 1
System Memory Multiplier: 16.00 (1600MHZ)
Performance Enhance: Standard
Dram Timing Selectable: Auto
QPI/VTT: 1.050V [1.190V]
Dram Voltage: 1.5V [1.55V]

Any suggestions would be appreciated before I send it off for the RMA.

Update:

Okay, so it seems now the computer is recognising that there is 16GB installed but it will not get past the Loading Operating System page, of in which case it wont allow me to boot in to Memtest. Therefore I must have some kind of setting incorrect?

 

[kristmace]

Well, if it is faulty then it's just not going to work. Might be worth clearing CMOS just to rule out the dodgy setting possibility.

 

[Idleman]

Have you tried just using 1 stick of the crucial ram and see if it boots and then try the other 1. If it boots with 1, but not the other, then it`s safe to RMA. It`s not uncommon for 1 of a matched pair to be faulty.

 

[Tenatious]

That's the thing.... it's fine with one of the crucials at a time but as soon as I put both together it wont boot. It's really bizarre. For example at the moment the computer is booted and stable with 12GB of ram in (2 x 4GB of the corsair and 1 x 4GB of the crucial). It will boot stable with either of the crucials in but not with both. The same is the case if I boot with a single crucial and no corsair and both crucials....

 

[Tenatious]

Anymore ideas on this?

 

[stulid]

Update the BIOS.

Run MEMtest.

Set the timings/voltage to the worse set of RAM.

 

[beejjacobs]

I'd just RMA them if you haven't already

 

[Tenatious]

Update the BIOS.

Run MEMtest.

Set the timings/voltage to the worse set of RAM.

Done all this. Still wont allow both of the Crucials to be placed in the board together. I just find it really odd that they work individually but not as a pair!