Kioxia and WD Unveil World's Fastest 3D NAND Flash Memory

Western Digital
(Image credit: Western Digital)

Kioxia and Western Digital have revealed their jointly developed 8th Generation BiCS 3D NAND memory device featuring 218 active layers. The new IC boasts a record-breaking 3200 MT/s interface speed that will allow developers to build high-performance storage subsystems (such as the industry's fastest client SSDs) using fewer 3D NAND chips. To enable a 3200 MT/s I/O, the two companies took a page from YMTC's Xtacking book. 

The first 8th Generation BiCS 3D TLC NAND device introduced this week features a 1Tb (128GB) capacity, a four-plane architecture to maximize internal parallelism and performance, and a 3200 MT/s interface speed (which will provide a peak sequential read/write speed of 400 MB/s). Kioxia and Western Digital are the first 3D NAND makers in the world to unveil a flash memory IC with a 3200 MT/s I/O, leapfrogging competitors by 33%. 

But while building the world's fastest 3D NAND memory device is an achievement by itself, it is interesting how the two companies achieved this. Kioxia's and Western Digital's 8th Generation BiCS 3D NAND memory features an innovative architecture called CBA (CMOS directly Bonded to Array), which resembles YMTC's recognized Xtacking.  

Normally, 3D NAND cells array resides next to or on top of its peripheral circuits like page buffers, sense amplifiers, charge pumps, and I/O. Meanwhile, from semiconductor manufacturing perspective, it is not exactly efficient to make memory and peripheral logic using the same fabrication technology. The CBA and Xtacking architectures involve production of 3D NAND cell array and I/O CMOS on separate wafers using optimal production nodes, something that allows it to maximize bit density of the memory array and I/O performance. 

In addition to the industry's fastest I/O, Kioxia and Western Digital claim that their latest 3D NAND IC also boasts the industry's highest bit density, though without elaborating what bit density we are looking at. Meanwhile, it is noteworthy that the introduced 8th Generation BiCS 3D TLC NAND can work in both 3D TLC and 3D QLC modes and therefore can potentially address both high-performance/high-capacity premium client and enterprise SSDs as well as inexpensive yet fast drives for client PCs or high-density datacenter-grade storage applications. 

Kioxia stated that it had commenced sampling its 8th Generation BiCS 3D NAND memory devices with a few chosen customers. However, the company has not provided any information regarding the timeline for the start of high-volume production of its latest flash memory. Since it takes a long time for makers of flash memory and SSD controllers to mate the former to the latter, NAND producers usually reveal new types of memory well before  mass production start. That said, expect 8th Gen BiCS 3D NAND on the market sometime in 2024, although we are speculating here. 

"Through our unique engineering partnership, we have successfully launched the eighth-generation BiCS Flash with the industry's highest bit density," said Masaki Momodomi, Chief Technology Officer at Kioxia Corporation. "I am pleased that Kioxia's sample shipments for limited customers have started. By applying CBA technology and scaling innovations, we've advanced our portfolio of 3D flash memory technologies for use in various data-centric applications, including smartphones, IoT devices, and data centers."

Anton Shilov
Freelance News Writer

Anton Shilov is a Freelance News Writer at Tom’s Hardware US. Over the past couple of decades, he has covered everything from CPUs and GPUs to supercomputers and from modern process technologies and latest fab tools to high-tech industry trends.

  • gg83
    does Kioxia/WD fab they're own chips? or are they like amd?
    Reply
  • cyrusfox
    gg83 said:
    does Kioxia/WD fab they're own chips? or are they like amd?
    NO they are not like AMD, They operate as a Joint Venture(Co-own the fabs/dev/production). They use to go by Toshiba/Sandisk.

    Toshiba transformed to Kioxia thanks to the Nuclear disaster in Japan. WD bought SanDisk and has essentially re-branded everything to WD, the only part that remains are the part numbers (SN850x).
    Kioxia has been neglecting the consumer space outside of OEMs, Large presence in professional/server market pushing different EDSFF form factor. WD is inverse, mostly consumer facing + OEM, with barely any server/datacenter products.

    Rumors of merging the companies have existed for awhile, There are similarities to the IMFlash(IMFT) Joint Venture Micron and Intel ran, although Kioxia doesn't have any other business so it would make more sense to me as a straight buyout from WD. The economics of co-development and manufacturing are more lucrative than doing independently. As such I would expect them either to continue in this partnership or for WD to attempt to buyout Kioxia as they appear to be the more successful partner with a more recognizable brand (Expensive marketing hit going from Toshiba to Kioxia). Also WD is working on emerging memory, Kioxia statements on different memory techs have been negative (Maybe for good reason see end of Optane).

    Compared to Hynix, Samsung, & Micron. Kioxia and WD are the ones to watch for disruption as neither is in the DRAM business and could see the most to gain by disrupting.
    Reply
  • gg83
    cyrusfox said:
    NO they are not like AMD, They operate as a Joint Venture(Co-own the fabs/dev/production). They use to go by Toshiba/Sandisk.

    Toshiba transformed to Kioxia thanks to the Nuclear disaster in Japan. WD bought SanDisk and has essentially re-branded everything to WD, the only part that remains are the part numbers (SN850x).
    Kioxia has been neglecting the consumer space outside of OEMs, Large presence in professional/server market pushing different EDSFF form factor. WD is inverse, mostly consumer facing + OEM, with barely any server/datacenter products.

    Rumors of merging the companies have existed for awhile, There are similarities to the IMFlash(IMFT) Joint Venture Micron and Intel ran, although Kioxia doesn't have any other business so it would make more sense to me as a straight buyout from WD. The economics of co-development and manufacturing are more lucrative than doing independently. As such I would expect them either to continue in this partnership or for WD to attempt to buyout Kioxia as they appear to be the more successful partner with a more recognizable brand (Expensive marketing hit going from Toshiba to Kioxia). Also WD is working on emerging memory, Kioxia statements on different memory techs have been negative (Maybe for good reason see end of Optane).

    Compared to Hynix, Samsung, & Micron. Kioxia and WD are the ones to watch for disruption as neither is in the DRAM business and could see the most to gain by disrupting.
    Awesome, thanks for the reply! I've been curious about the compute on memory concept. I wonder of WD will pursue that at all
    Reply