A month ago, WD and Toshiba each put out releases related to their BiCS 3D Flash memory. WD announced 96 layers (BiCS4) as their next capacity node, while Toshiba announced them reliably storing four bits per cell (QLC).
WD recently did their own press release related to QLC, partially mirroring Toshiba's announcement, but this one had some additional details on capacity per die, as well as stating their associated technology name used for these shifts. TLC was referred to as "X3", and "X4" is the name for their QLC tech as applied to BiCS. The WD release stated that X4 tech, applied to BiCS3, yields 768Gbit (96GB) per die vs. 512Gbit (64GB) per die for X3 (TLC). Bear in mind that while the release (and the math) states this is a 50% increase, moving from TLC to QLC with the same number of cells does only yields a 33% increase, meaning X4 BiCS3 dies need to have additional cells (and footprint) to add that extra 17%.
The release ends by hinting at X4 being applied to BiCS4 in the future, which is definitely exciting. Merging the two recently announced technologies would yield a theoretical 96-layer BiCS4 die, using X4 QLC technology, yielding 1152 Gbit (144GB) per die. A 16 die stack of which would come to 2,304 GB (1.5x the previously stated 1.5TB figure). The 2304 figure might appear incorrect but consider that we are multiplying two 'odd' capacities together (768 Gbit (1.5x512Gbit for TLC) and 96 layers (1.5×64 for X3).
Press blast appears after the break.
WESTERN DIGITAL ANNOUNCES FOUR-BITS-PER-CELL (X4) TECHNOLOGY ON 3D NAND
Further Enhances Industry Leadership in Multi-Level Cell Storage Builds on X4 Expertise in 2D NAND
SAN JOSE, Calif. — July 24, 2017 — Western Digital Corp. (NASDAQ: WDC) today announced its successful development of four bits per cell, X4, flash memory architecture offering on 64-layer 3D NAND, BiCS3, technology. Building on its pioneering innovation of X4 for 2D NAND technology and past success in commercializing it, the company has now developed X4 for 3D NAND by leveraging its deep vertical integration capabilities. These include silicon wafer processing, device engineering to provide sixteen distinct data levels in every storage node, and system expertise for overall flash management. BiCS3 X4 technology delivers an industry-leading storage capacity of 768 gigabits on a single chip, a 50 percent increase from the prior 512 gigabit chip that was enabled with the three bits per cell (X3) architecture. Western Digital will showcase removable products and solid-state drives built with BiCS3 X4 and systems capabilities in August at the Flash Memory Summit in Santa Clara, California.
“The implementation of X4 architecture on BiCS3 is a significant development for Western Digital as it demonstrates our continued leadership in NAND flash technology, and it also enables us to offer an expanded choice of storage solutions for our customers,” said Dr. Siva Sivaram, executive vice president, Memory Technology, Western Digital.
“The most striking aspect in today’s announcement is the use of innovative techniques in the X4 architecture that allows our BiCS3 X4 to deliver performance attributes comparable to those in BiCS3 X3. The narrowing of the performance gap between the X4 and X3 architectures is an important and differentiating capability for us, and it should help drive broader market acceptance of X4 technology over the next several years.”
This latest achievement follows a nearly three-decade long legacy of industry firsts in flash innovation, including the industry’s multi-level cell (MLC) flash technologies using two bits (X2) and three bits (X3) per cell.
The company expects to productize its 3D NAND X4 technology across multiple end-use applications that can take advantage of the higher capacity points supported by X4. Future generations of 3D NAND technology, including the 96-layer BiCS4, are also expected to feature X4 capabilities.
About Western Digital
Western Digital is an industry-leading provider of storage technologies and solutions that enable people to create, leverage, experience and preserve data. The company addresses ever-changing market needs by providing a full portfolio of compelling, high-quality storage solutions with customer-focused innovation, high efficiency, flexibility and speed. Our products are marketed under the HGST, SanDisk and WD brands to OEMs, distributors, resellers, cloud infrastructure providers and consumers. Financial and investor information is available on the company's Investor Relations website at investor.wdc.com.
Western Digital is a registered trademark or trademark of Western Digital Corporation or its affiliates in the U.S. and/or other countries. All other marks are the property of their respective owners. © 2017 Western Digital Corporation or its affiliates. All rights reserved.
1 – 1 gigabit = 1,000,000,000 bytes. Actual user storage less.