I got this board new for a friend's build, along with a 10700 and 2x32GB Corsair Vengeance LPX DDR4 sticks.
It came with bios 403 (original release) therefore it must be one of the early batches... and, sure enough, it is completely unstable when populating both DIMM slots.
Tried around 4 bios versions, the problem remained the same.
I'm not even talking about enabling XMP here. The board cannot install Windows even with the RAM running at 2133Mhz. This is known good ram.
Funny thing is, it passes overnight repeating memtest tests. But even at the slightest hint of CPU utilization, the board instantly reboots.
With only one DIMM slot populated, it seems to work fine, even with XMP enabled.
Seeing as I have to RMA this board through the local e-tailer I bought it from, which will probably end in me trying to explain what the problem is, and then receiving back the same board, only in worse condition - because, apparently, I can't RMA the board with Asus directly (after entering the serial number in the RMA form, I get a "please RMA with your dealer" message).
Is there anything I might be missing? Or is a protracted and unnecessarily convoluted RMA process the only way to have dual channel RAM on this board? The various horror stories posted here and on Amazon/Newegg re: this board's issues with RAM paint a worrying picture.