Data Centre

Storage

Quad goals: Western Digital clambers aboard the 4bits/cell wagon

The bit number explosion gets bigger still

By Chris Mellor

11 SHARE

In the flash numbers game Western Digital's 3D, 64-layer NAND is being armed with 4bits/cell (quad-level cell, QLC) and bit-cost scaling (BiCS3) technology.

WD's announcement follows joint-venture partner and legal war opponent Toshiba's QLC reveal in June.

QLC flash chips have a third more cells and double the data density of TLC (triple-level cell) flash.

Once upon a time flash chips came with just one layer of 1bit cells. With today's 64-layer, 3bits/cell chips there has been an explosive increase in the number of bits on a chip and this is set to continue.

Its QLC chip has a 768Gb capacity. Dr Siva Sivaram, executive vice president of memory technology for SanDisk, bigged up WD's QLC implementation. "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," he said.

In other words, its QLC flash performs pretty much at the same level as its 3bits/cell TLC flash. However, it's generally recognised that QLC's endurance will be significantly shorter than that of TLC flash, rendering it suitable for fast-access archival data applications and other read-often, write-rarely use cases.

But its high capacity means that over-provisioning in QLC drives can be used to extend the effective life.

WD will have QLC SSD and removable drives on show at the Flash Memory Summit in Santa Clara next month. Martin Fink, WD executive vice president and CTO has a speaking slot at the event.

WD expects that its in-development 96-layer 3D NAND will come in QLC form as well. ®

Sign up to our NewsletterGet IT in your inbox daily

11 Comments

More from The Register

NAND the beat goes on: Samsung to fling out 96-layer 3D NAND chip

QLC will take SSD capacity to another level

Hot NAND: Samsung wheels out 30TB SSD monster

It's another whopper: Fabulous capacity or blast radius nightmare

Blackout at Samsung NAND factory destroys chunk of global supply

Just what the world needs after a year of component shortages

3 is the magic number (of bits): Flip 'em at once and your ECC protection can be Rowhammer'd

Dutch boffins prove it is possible to evade memory-busting attack mitigations

Who needs NAND when rust never sleeps? Seagate dines out on nearline disk drive boom

Getting fat off the NAND's just a flash in the pan...

No pain, no $1.3bn Bain gain: Seagate slips Tosh/WD chippery into Nytro SSD ranges

NAND that... is how you get skin in the flash game

What the PUC: SK Hynix next to join big boys in 96-layer 3D NAND land

Whether you Periphery Under Cell or Core Over Periphery, it all means smaller chips

Flash, Sam, wallop: Samsung crashes ahead as top NAND chip flinger

According to these here estimates, anyway

Seagate and Western Digital neck-and-neck at the nearline drive-in

Seagate ships more units, WD more capacity – it's a wash

Number-three disk drive maker Toshiba isn't shy about shipping 23.4m spinners in 3Q18

Will it increase capacity in a tuned-in MAMR?