The new UFS 2.1 storage memory chips integrate Toshiba's 64-layer BICS 3D TLC NAND technology, and will target mobile devices such as smartphones, tablets and standalone VR headsets. Providing sequential read speeds of up to 900 MB/s, sequential write speeds of up to 180 MB/s and improved random read/write performance for the 64 GB memory chip, Toshiba promises even better specs for the higher capacity versions.
https://www.notebookcheck.net/Toshiba-announces-UFS-2-1-mobile-storage-chips-with-up-to-900-MB-s-read-speeds.268062.0.html