JEDEC specifies that the pull-up resistor for the SAVE_N pin on NVDIMMs belongs on the motherboard.
Micron designs NVDIMM with and without the pull-up resistor to support all customers, since some current motherboards do not include the SAVE_N pull-up resistor. However, we believe this recent specification pushes NVDIMM architecture in the right direction, because it eliminates ambiguity.
Diagram of JEDEC Specification (click to enlarge)
Placing the pull-up resistor on the motherboard allows that resistor to be tuned to the specific SAVE_N load of each design. This gives customers the flexibility to develop their systems for their specific requirements.
Micron recommends customers place the SAVE_N pull-up resistor on the motherboard for all future designs and follow JEDEC specification.