The sequential read speed of UFS 4.0 is 4200MBps, while the sequential write speed is 2800MBps. For your information, UFS 3.1 can provide sequential read speeds of up to 2100MBps and sequential write speeds of up to 1200MBps. That's more than double the speed of UFS 3.1!!
Samsung has significantly enhanced the UFS storage standard is power efficiency. The UFS 4.0 standard uses 46% less power than UFS 3.1 while providing double the performance. That implies your next flagship smartphone will have considerably quicker storage without sacrificing battery life. It can effectively give a sequential read speed of 6.0MBps for every mA.
Samsung's UFS 4.0 storage has a maximum size of 11mm length, 13mm width, and 1mm height. Samsung has also stated that the 4.0 standard would support capacities of up to 1TB (UFS 3.1 only supported capacities of up to 512GB), which is more than enough for portable devices.