My problem is that only the DIMMs in the first 4 slots (A1,A2,B1,B2) are being recognized. All 8 sots will show up in the BIOS POST, but only the 4 in those slots will count towards the total onboard RAM. I've confirmed this by removing and shuffling my DIMMs around and rebooting several times.
Am I missing something to be able to set this mobo up for 32 gb ram?
The documentation for the Asus Rampage IV Extreme gives no indication on the supported memory vendors list that it supports 8 sticks of memory or 32GB of RAM. Having said that, they tend to lie, my Asus P5E3 "supports 8GB' but runs just fine with 16GB of DDR3-1600.
Ensure your BIOS is updated to the latest version as this will have a significant impact on your RAM compatibility. You should be at BIOS 3301. If you're at 1404 or less then you will have run the BIOS converter first.
Their specs are:
8 x DIMM, Max. 64GB, DDR3 2400(O.C.)/2133(O.C.)/1866/1600/1333/1066 MHz Non-ECC, Un-buffered Memory
Quad Channel Memory Architecture
Supports Intel® Extreme Memory Profile (XMP)
* Hyper DIMM support is subject to the physical characteristics of individual CPUs.
* Refer to www.asus.com or user manual for the Memory QVL (Qualified Vendors Lists).