Universal Flash Storage, officially abbreviated as UFS, is a flash storage specification for digital cameras, mobile phones and consumer electronic devices. It aims to bring higher data transfer speed and increased reliability to flash memory storage, while reducing market confusion and removing the need for different adapters for different types of card.
Overview
The proposed flash memory specification is supported by leading firms in the consumer electronics industry such as Nokia, Sony Ericsson, Texas Instruments, STMicroelectronics, Samsung, Micron, SK Hynix. UFS is positioned as a replacement for eMMCs and SD cards. The electrical interface for UFS uses the M-PHY, developed by the MIPI Alliance, a high-speed serial interface targeting 2.9 Gbit/s per lane with up-scalability to 5.8 Gbit/s per lane. UFS implements a full-duplex serial LVDS interface that scales better to higher bandwidths than the 8-lane parallel interface of eMMCs. Unlike eMMC, Universal Flash Storage is based on the SCSI architectural model and supports SCSI Tagged Command Queuing. The standard is developed by, and available from, the JEDEC Solid State Technology Association. In September 2013, JEDEC published JESD220B UFS 2.0. JESD220B Universal Flash Storage v2.0 offers increased link bandwidth for performance improvement, a security features extension and additional power saving features over the UFS v1.1. The Linux kernel supports UFS. On 30 January 2018 JEDEC published version 3.0 of the UFS standard, with a higher 11.6 Gbit/s data rate per lane with the use of MIPI M-PHY v4.1 and UniProSM v1.8. At the MWC 2018, Samsung unveiled embedded UFS v3.0 and uMCP solutions. On 30 January 2020 JEDEC published version 3.1 of the UFS standard. UFS 3.1 introduces Write Booster, Deep Sleep, Performance Throttling Notification and Host Performance Booster for faster, more power efficient and cheaper UFS solutions. The Host Performance Booster feature is optional. UFS uses NAND flash. It may use multiple stacked 3D TLC NAND flash dies with an integrated controller.
Complementary UFS standards
On 30 March 2016, JEDEC published version 1.0 of the UFS Card Extension Standard, which offered many of the features and much of the same functionality as the existing UFS 2.0 embedded device standard, but with additions and modifications for removable cards. Also in March 2016, JEDEC published version 1.1 of the UFS Unified Memory Extension, version 2.1 of the UFS Host Controller Interface standard, and version 1.1A of the UFSHCI Unified Memory Extension standard. On January 30, 2018, the UFS Card Extension standard was updated to version 1.1, and the UFSHCI standard was updated to version 3.0, to align with UFS version 3.0.
Notable devices
On 7 July 2016, Samsung introduced the first UFS cards in 32, 64, 128, and 256 GB storage capacities. The cards are based on the UFS 1.0 Card Extension Standard. The 256GB version will offer sequential read performance up to 530 MB/s and sequential write performance up to 170 MB/s and random performance of 40,000 read IOPS and 35,000 write IOPS. On 17 November 2016, Qualcomm announced the Snapdragon 835SoC with support for UFS 2.1. The Snapdragon 835 also supports SD Card Version 3.0 and USB 3.1 Type-C. On 14 May 2019, OnePlus introduced the OnePlus 7 and OnePlus 7 Pro, the first phones to feature built-in UFS 3.0.
Version comparison
UFS
UFS Card
Implementation
UFS 2.0 in Snapdragon 820 and 821. Kirin 950 and 955. Exynos 7420 UFS 2.1 in Snapdragon 712, 730G, 835, 845 and 850. Kirin 960, 970 and 980. Exynos 9609, 9610, 9611, 9810 and 980. UFS 3.0 in Snapdragon 855. Exynos 9820/9825, and Kirin 990.
