Memory Compatability Question for X99 Motheboards

[Markess]

The specifications of most of the Asrock consumer X99 chipset motherboards include compatibility with ECC Registered DRAM, but the Memory Support/QVL lists don't seem to mention compatible physical RAM configurations. I already have 64GB (16GBx4) of Samsung DDR4 (M393A2G40DB0-CPB) which is in a 2Rx4 configuration. I know from experience on the server side that some systems work with only one physical layout type (2Rx4, 1Rx8, or 2Rx8 for example), while others work with any. So, I thought it best to check, before I buy.

Does anyone know if this 2Rx4 configured RAM is compatible with any of the ASRock X99 motherboards?

Thank you.