32 to 64gb RAM upgrade trouble. Windows reports 64.0 GB (31.2 GB usable)

[Catalin8787]

Hi, please help!
I have an i7 4820k with a ASUS P9X79 mainboard, running Windows 7 Ultimate.
I had 32Gb (4x8) of G.Skill RipjawsZ 2133 DDR3, running at 1600 mhz (max for my CPU).
I bought another 32GB of the exact same model, and got them running. But windows reports only 31.2 GB as usable out of 64. Sp basically they are running, but aren't being used.

I wasn't hoping on running XMP, because I'm running two pairs of ram. But the weird thing is when I enter the BIOS, it appears the new sticks run at 1333 and the old ones at 1666. I tried changing to 1666 and then 1333.

and my cpu is overheating. help!
LE: had to quickly restart, the Asus utility warned me of 100 degrees Celsius cpu temperature, weird. Now runs normally at 45 degrees.

MLE:
FIXED
Got all 64gb to work by disabling "Windows Max memory" in msconfig.

After running the windows memory diagnostic tool, I realised I was getting some ram hardware errors.
It was just a question of getting all the 8 memory sticks properly inserted in their slots, cramped MB design being an issue.

I fixed any speed or voltage issue by using XMP profile 2. Did not expect it to work, being two kits, but it did.

 

[Lutfij]

Can you parse a link to both ram kits? If possible a pic of both ram kits sticks(stickered information). Are you on the latest BIOS update for your motherboard? I think the new ram kit your purchased might be faulty to begin with if memtest86 comes up without any errors on your original ram kit. You will need to run 10 passes for each stick in each slot and gradually work your way up till you rule out the faulty stick/faulty slot on the board.

You can also try manually inputting the voltage, timings and frequency in BIOS and see if that changes your experience. On a last note, include your specs like so:
CPU:
Motherboard:
Ram:
SSD/HDD:
GPU:
PSU:
Chassis:
OS:

 

[shknawe]

so if im reading your story correctly you already fixed your problem?