https://www.theregister.co.uk/2019/05/29/intel_speeds_up_optane_caching_memory_with_pci_lane_doubling/

Intel has added two more PCIe lanes to speed up its Optane memory disk drive caching device and tweaked power handling for a lower deep-sleep power draw.

Back in January 2017, Intel released 16 and 32GB Optane Memory products in an M.2 card format, which were meant to cache disk drives using its Rapid Storage Technology (RST). These became the Optane Memory M10 devices, which had two PCIe gen 3 lanes.