Ann: Megabit Success, page-1585

"The defining requirements for all the technologies intended to be used for anSCM are:
• High R/W throughput: on the order of 1 GB/s.
• High write endurance: much better than that delivered by NAND, on the orderof 10^12.
• Low read latency: on the order of 100 ns.
• Non-volatility: no or only sporadic need for refresh of stored data, i.e., ideallythe 10-year retention that flash technology can offer.
• A good scaling perspective, with the potential to overcome limits that are currentlyrestricting NAND and DRAM scaling perspectives."

DOI 10.1007/978-3-319-47724-4

I generally think if we can get 10 billion endurance cycles that will be enough. We already smash the read speed and the non-volatility.
Need to define retention and scaling.