The Optane Memory M15 shows a pretty significant performance boost compared to the existing M10 series, mostly due to the PCIe 3.0 x4 interface. This pushed the sequential read and write performance to up to 2,000MB/s and 900MB/s, respectively. The random 4K read and write now peaks at up to 450K IOPS and 220K IPS, respectively.
The new Optane M15 series is still based on a standard M.2 2280 form factor and still offers the same endurance rating of 200GB WPD or up to 365 TWB. It still supports Intel's 7th gen or newer platform and is backed by the same 5-year warranty.
According to Intel, the new Optane Memory M15 series will be available in Q3 2019.