3D Xpoint latency is still several times slower than DRAM. 3D Xpoint also still suffers from limited endurance. 3D Xpoint NVDIMMs will be used as pmem block devices, not as primary RAM.
For DRAM-equivalent latency and endurance you need STT-MRAM, which has already been available in DDR3-compatible DIMMs. Both STT-MRAM and 3D Xpoint will be available in DDR4-compatible DIMMS too but only STT-MRAM will run fast enough and long enough to replace DRAM.
For DRAM-equivalent latency and endurance you need STT-MRAM, which has already been available in DDR3-compatible DIMMs. Both STT-MRAM and 3D Xpoint will be available in DDR4-compatible DIMMS too but only STT-MRAM will run fast enough and long enough to replace DRAM.