Kingston shows one 32 GB DDR3L 1333 MHz 1.35V memory module (part number KVR13LR9Q4/32) compatible with SuperMicro's X8DTH-6F motherboard.
According to SuperMicro's documentation the speed would drop to 800 MHz for this quad ranked part in either 1 or 2 DPC configurations.
Still, 384 GB on a dual socket/12 DIMM motherboard is not bad!
At around $460/DIMM retail, however, that much memory would run over $5,500...