KIOXIA Introduces Next-Generation UFS Ver. 4.0 Devices

New 256GB, 512GB and 1TB Devices Allow Smartphones and Mobile Applications to Take Full Advantage of 5G Networks

SAN JOSE, Calif., May 30, 2023 – Continuing to move Universal Flash Storage1 (UFS) technology forward,  KIOXIA America, Inc. today announced sampling2 of new, higher performing UFS Ver. 4.0 embedded flash memory devices3. These devices deliver fast embedded storage transfer speeds in a small package size and are targeted to a variety of next-generation mobile applications, including leading-edge smartphones. The improved performance3 of UFS products from KIOXIA enables these applications to take advantage of 5G’s connectivity benefits, leading to faster downloads, reduced lag time and an improved user experience.

UFS Ver. 4.0 devices from KIOXIA integrate the company’s innovative BiCS FLASH™ 3D flash memory and a controller in a JEDEC-standard package. UFS 4.0 incorporates MIPI M-PHY 5.0 and UniPro 2.0 and supports theoretical interface speeds of up to 23.2 gigabits per second (Gbp/s) per lane or 46.4 Gbp/s per device. UFS 4.0 is backward compatible with UFS 3.1.

“Once again KIOXIA is maintaining its leadership in UFS, with our pipeline of newer, faster performing UFS devices,” noted Scott Beekman, vice president, Memory Business Unit, for KIOXIA America, Inc.  “This is our second generation of UFS 4.0 devices, which were developed to keep pushing the performance boundaries from generation to generation.”

Key Features include:

  • Performance improvement over previous generation4: +18% sequential write, +30% random write and +13% random read.
  • Supports High Speed Link Startup Sequence (HS-LSS) features: With conventional UFS, Link Startup (M-PHY and UniPro initialization sequence) between device and host is performed at low-speed PWM-G1 (3~9 megabits per second5), but with HS-LSS, it can be performed at a faster HS-G1 Rate A (1248 megabits per second5). This is expected to reduce the time for Link Startup by approximately 70% compared to the conventional method.
  • Enhances security: By utilizing Advanced RPMB (Replay Protected Memory Block) for faster read and write access to security data, such as user credentials on RPMB area, and RPMB Purge to ensure discarded data may be sanitized securely and rapidly.
  • Supports Extended Initiator ID (Ext-IID): Intended to be used with Multi Circular Queue (MCQ) at the UFS 4.0 host controller for improved random performance.

For more information, please visit

About KIOXIA America, Inc.

KIOXIA America, Inc. is the U.S.-based subsidiary of KIOXIA Corporation, a leading worldwide supplier of flash memory and solid state drives (SSDs). From the invention of flash memory to today’s breakthrough BiCS FLASH™ 3D flash memory technology, KIOXIA continues to pioneer innovative memory, SSD and software solutions that enrich people's lives and expand society's horizons. The company's innovative BiCS FLASH™ 3D flash memory technology is shaping the future of storage in high-density applications, including advanced smartphones, PCs, SSDs, automotive, and data centers.


1: Universal Flash Storage (UFS) is a product category for a class of embedded memory products built to the JEDEC UFS standard specification. Due to its serial interface, UFS supports full duplexing, which enables both concurrent reading and writing between the host processor and UFS device.
2: The company’s newest devices are supported in three capacities: 256 gigabytes (GB), 512GB and 1 terabyte (TB). Sample shipments of the 256GB and 512GB device began this month, with the 1TB device scheduled to follow after October. Specification of the samples may differ from commercial products.
3: Comparing KIOXIA’s new 512GB UFS Ver. 4.0 embedded flash memory device and KIOXIA’s previous generation 512GB UFS Ver. 4.0 embedded flash memory device (part number THGJFJT2T85BAT0).
4: KIOXIA previous generation 512GB device “THGJFJT2T85BAT0”.
5: PWM-G1 communication speed depends on the host and the device.

Read and write speeds are the best values obtained in a specific test environment at KIOXIA and KIOXIA warrants neither read nor write speeds in individual devices. Read and write speed may vary depending on device used and file size read or written.

In every mention of a KIOXIA product: Product density is identified based on the density of memory chip(s) within the Product, not the amount of memory capacity available for data storage by the end user. Consumer-usable capacity will be less due to overhead data areas, formatting, bad blocks, and other constraints, and may also vary based on the host device and application. For details, please refer to applicable product specifications. The definition of 1KB = 2^10 bytes = 1,024 bytes. The definition of 1Gb = 2^30 bits = 1,073,741,824 bits. The definition of 1GB = 2^30 bytes = 1,073,741,824 bytes. 1Tb = 2^40 bits = 1,099,511,627,776 bits.

All company names, product names and service names may be trademarks of their respective companies.

Information in this press release, including product pricing and specifications, content of services, and contact information is current and believed to be accurate on the date of the announcement, but is subject to change without prior notice. Technical and application information contained here is subject to the most recent applicable KIOXIA product specifications.