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Asus Z68 mobo only sees half the RAM

qubit

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My new(ish) Asus P8Z68-V PRO/GEN3 mobo only sees half of the 32GB RAM fitted and I'm not sure what to do about it. The BIOS sees only 16GB and therefore so does Windows.

I've tried a couple of things, but it didn't fix it. Note that since I have the huge Noctua NH-D14 fitted I can't physically get to my RAM modules without pulling out the mobo, removing the backplate and fitting a standard cooler. It's ironic that the one problem I didn't want to get with this cooler, I did.

Basically, I initially fitted 4 x 8GB Corsair Vengeance 1600MHz modules for 32GB total, before I bought the Noctua. However, I'd bought the high profile modules by mistake, so I bought two low profile versions of the same spec which allowed me to fit the cooler.

To troubleshoot, I cleared the CMOS RAM by moving the jumper but that didn't help. I then went back one generation of BIOS from 3202 to 402, the one the mobo shipped with and that didn't help either. Running the 2700K CPU at stock didn't help either.

Note that the modules are arranged internally as 2 banks of 4GB, so obviously the mobo is seeing only one bank.

So, short of taking my PC to pieces and swapping sticks around (I still have the original Vengeance modules) I'm stuck, as there's not many configuration options available for RAM modules which would alter how much RAM is seen. And yes, I did try googling it. ;)

Please see my specs for full details of what's in my PC.
 
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INSTG8R

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I know in a recent BIOS update my Sabertooth they added a new option for Memory Remap Feature under System Agent Configuration. Now it was Enabled by default so this may not help at all. But just shooting ideas.
 
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Hi

As I understand it you have placed the low profile mem modules in DIMM_A1 & DIMM_A2 and the high profile modules in DIMM_B1 & DIMM_B2 to aviod contact with the noctua cooler; this could be / is an issue as they need to be in pairs using DIMM_A1 & DIMM_B1 or DIMM_A2 & DIMM_B2

keep the low profile sticks in the system and remove the other / or swap the cooler out; maybe an option

Hope this helps

atb (all the best)

Law-II
 
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qubit

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INSTG8R: Unfortunately, the memory remapping didn't work.

Law: I have a feeling you're right about this, despite the fact that the modules are electrically the same, since it's only the heatspreader that's different between them. The BIOS does see all four modules and displays their specs, which are identical between all the modules. The only difference is one letter in the part number.

I think I'll have to bite the bullet and take the whole thing apart and play around with it. If alternating the memory modules fixes the 16/32 issue, then I have two options:

1 buy more identical low profile modules

2 try and swap the heatspreaders round so the cooler will fit

I think option 1 is more sensible, because removing the heatspreader voids the warranty (breaks the seal) and it may be glued down anyway, preventing easy removal.
 

Athlon2K15

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Vengeance uses double sided tape,and actually if you can just pop one corner the entire spreader will fall of.

Mind you wont be able to put it back on without additional tape being needed
 

qubit

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Processor Intel Core i7-2700K @ 4GHz
Motherboard Asus P8Z68-V PRO/GEN3
Cooling Noctua NH-D14
Memory 16GB (2 x 8GB Corsair Vengeance Black DDR3 PC3-12800 C9 1600MHz)
Video Card(s) MSI RTX 2080 SUPER Gaming X Trio
Storage Samsung 850 Pro 256GB | WD Black 4TB | WD Blue 6TB
Display(s) ASUS ROG Strix XG27UQR (4K, 144Hz, G-SYNC compatible) | Asus MG28UQ (4K, 60Hz, FreeSync compatible)
Case Cooler Master HAF 922
Audio Device(s) Creative Sound Blaster X-Fi Fatal1ty PCIe
Power Supply Corsair AX1600i
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Software Windows 10 Pro 64-bit
I think I saw screws holding the tall heatspreaders together. I don't know about the low profile ones. I'll bear this in mind. :)
 
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