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X79-Deluxe not seeing all 32GB

SirBC
Level 7
Windows is only seeing 24GB of my 32GB Corsair Vengance Pro memory (bought as a 8GB x 4 kit). The Bios also reports 24GB total memory even though it shows all four 8GB modules:



Troubleshooting steps I've taken so far:


  • At first Windows would only see 16GB. I was using Windows 7 Home and upgraded to Pro so there was no longer a 16GB limit, but it was now only seeing 24GB after the upgrade
  • Tried each stick 1 at a time in the first slot and was able to boot into windows with 8GB showing for each stick
  • Cleared CMOS with only 1 8GB stick present, booted to windows, shutdown and installed all 32GB
  • Installed latest BIOS
    [*}Did a memtest86+ 1 stick at a time, all passed


The QVL lists the Corsair Dominator 8GB x4 kits but not the Dominator Pro which I have, not sure if that is the issue. Any ideas what the issue might be?

16,324 Views
18 REPLIES 18

Chino
Level 15
Welcome to the ROG forums, SirBC.

If you're not running the latest BIOS, please update to the latest one using a USB pendrive and the EZ Flash Utility in the BIOS. Also have you tried doing 1 to 2 cycles of Memtest86+ on the whole kit after running tests on them individually?

HiVizMan
Level 40
Please test each slot with all the sticks, you may find that one stick will not work with one slot.
To help us help you - please provide as much information about your system and the problem as possible.

Raja
Level 13
This platform will drop DIMMs or ranks if the memory isn't stable or has a fault. If all the slots work individually, then it's down to settings. If one slot does not work then CPU socket might have bent/misalinged pin, DIMM socket issue, BGA issue under socket or trace issue. This is all assuming all four DIMMs work individually.


If it's a setting issue, you can also enable MCH Recheck in the DRAM Timing section of UEFI. Doing so will force the memory controller to keep retraining DIMMs that don't map first time. The board will loop POST routines and this will extend POST time. Of course, one can negate that happening by altering any timings that are too tight and tuning voltages. But I'll let you debug everything above first.

SirBC
Level 7
Thanks guys, I'll check each module separately in each slot and go from there.

SirBC
Level 7
I'm about ready to start testing every slot/stick, just wondering if I need to fully boot into windows or can I just boot into BIOS?

HiVizMan
Level 40
If you use the guide in my sig it is all explained.
To help us help you - please provide as much information about your system and the problem as possible.

SirBC
Level 7
All sticks fail in slot B1 and work in the others. So I will check for bent pins on the cpu, and if it's not that, should I RMA the mobo at that point?

HiVizMan
Level 40
Inspect the memory slot and ensure there is no contaminant in the slot itself. That does happen.

Check the socket too, and then reseat the CPU and try just that slot again.

if still no go RMA the motherboard.
To help us help you - please provide as much information about your system and the problem as possible.

D3spereaux
Level 7
Hi,
You have the same problem as me.
On my board fail slot C1. I tested this slot on two kits of memory (Crucial and Corsair), in both cases did not work slot C1.
It looks like X79 Deluxe have trouble with memory slots :-(.
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