Tuesday, September 7th 2021

Western Digital Reimagines The Hard Drive with OptiNAND Technology

At the company's HDD Reimagine event today, Western Digital Corp. (NASDAQ: WDC) introduced a new flash-enhanced drive architecture that breaks traditional boundaries of storage. Building on the company's unique ability to innovate with HDD and flash, the new storage architecture with OptiNAND technology optimizes and integrates HDDs with iNAND embedded flash drives. This gives customers - like hyperscale cloud, CSPs, enterprises, smart video surveillance partners, NAS suppliers and more - a solution to meet the exponential growth in data creation by delivering the capacity, performance and reliability needed to store vast amounts of data today and well into the future.

Leveraging industry-first technologies including triple-stage actuator (TSA) and HelioSeal technology, the first products featuring the new drive architecture will deliver an unsurpassed 2.2 TB per platter, extending capacities gains on proven ePMR technology. Setting a new industry milestone, Western Digital has shipped samples of new nine-disk, 20 TB ePMR flash-enhanced drives with OptiNAND technology to select customers.
"Western Digital has a history of hard drive architecture innovations, such as when HGST (now part of Western Digital) first hermetically sealed and shipped helium HDDs in 2013," said Ed Burns, research director for hard disk drives at IDC. "Driven by the growth of AI, ML, blockchain, IoT, sensors and more, there's no doubt that new storage innovations are needed to store and protect today's data growth, especially at scale. As the only company manufacturing both flash and HDDs, Western Digital can uniquely leverage their in-house capabilities to extend the areal density curve of ePMR drives for generations to come, helping customers meet the growing demands of a digital economy."

"This new architecture is a natural extension of Western Digital's strengths and capabilities, delivering a new evolution of storage to the market," said Billy Chen, vice president of New H3C Group, president of Compute and Storage Product Line. "As an early customer, the OptiNAND technology is exciting as it will help us meet our storage needs for years to come."

New Flash-Enhanced Drive with OptiNAND Technology
Unlike a hybrid drive where flash is used to store user data, the new architecture is a breakthrough in storage that works differently, enabling advances on multiple dimensions of storage capability. By adding vertically integrated iNAND to its world-class HDDs, and with enhanced firmware algorithm and SoC innovations, Western Digital's flash-enhanced drives with OptiNAND technology deliver improved capacity, performance and reliability to help customers meet growing storage demands. A technology brief can be found here. Highlights include:
  • Capacity: The drive works smarter, with enhanced firmware algorithms taking advantage of expanded metadata that has been offloaded to the iNAND, enabling more tracks per inch (TPI) with resulting increased areal density.
  • Performance: Drive latency is improved with proprietary optimizations to drive firmware focused on requiring fewer adjacent track interference (ATI) refreshes and reducing the need for write cache flushes in write cache-enabled mode.
  • Reliability: Nearly 50x more customer data can be retained in the event of an emergency power off (EPO) scenario, and with Western Digital's unique capabilities in vertically integrated supply, design, development, testing and qualification of flash-enhanced drives, customers can count on the drive's reliability.
"With our IP and world-class development teams in HDD and flash, we are able to continuously push the boundaries of innovation to improve our customers' storage infrastructure," said Siva Sivaram, president of Global Technology and Strategy, Western Digital. "We have had an extraordinary journey of HDD innovation. We changed everything with HelioSeal in 2013; were first to ship energy-assisted HDDs in volume in 2019; and now we're going to lead again with OptiNAND technology. This architecture will underpin our HDD technology roadmap for multiple generations as we expect that an ePMR HDD with OptiNAND will reach 50TB1 in the second half of the decade."

Availability
The new flash-enhanced drive architecture with OptiNAND technology will be available across the company's portfolio of drives and storage platforms. It will also serve as the foundation for future designs and innovations, with further advances to come in intelligence, reliability, capacity and time-to-market value. The company will begin announcing market-specific, purpose-built products across its portfolio later this year.
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27 Comments on Western Digital Reimagines The Hard Drive with OptiNAND Technology

#1
Muser99
PR and a marketing waffle!
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#2
ExcuseMeWtf
And they will swap NAND chips for worse later anyways.
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#3
Chaitanya
ExcuseMeWtfAnd they will swap NAND chips for worse later anyways.
Also use SMR as drive fills up to increase density on spinning disc.
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#5
TheLostSwede
ChaitanyaAlso use SMR as drive fills up to increase density on spinning disc.
These are not SMR drives.
CrackongSSHD reinvented ?
No, apparently not, as the flash isn't used for file storage unless there's a power cut to the drive.
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#6
Crackong
TheLostSwedeNo, apparently not, as the flash isn't used for file storage unless there's a power cut to the drive.
But it says "write cache-enabled mode".

Isn't it just an SSHD ?
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#7
bug
I can't pretend I understood how this thing works, but I wonder whether we need to update our recovery tools to deal with this "breakthrough".
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#9
DeathtoGnomes
TheLostSwedeNo, apparently not, as the flash isn't used for file storage unless there's a power cut to the drive.
If it looks like a duck... :p
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#10
TheLostSwede
CrackongBut it says "write cache-enabled mode".

Isn't it just an SSHD ?
That's not what other sites have reported. It literally says "Unlike a hybrid drive where flash is used to store user data" in the press release above.
These drives still have a cache, it's just not part of the iNAND.
Unlike SSHDs, the OptiNAND drives do not store any user data at all during normal operation. Instead, the NAND is being used to store metadata from HDD operation in order to improve capacity, performance, and reliability.
www.anandtech.com/show/16920/western-digital-reimagines-hdd-flash-integration-with-optinand
Chaitanyablocksandfiles.com/2020/04/23/western-digital-blog-wd-red-nas-smr-drives-overuse/
And this has what to do with the product announcement above?
This is an ePMR drive.
bugI can't pretend I understood how this thing works, but I wonder whether we need to update our recovery tools to deal with this "breakthrough".
Possibly, considering the metadata is stored in the flash. I guess it would be tricky to recover at least some data without it.
DeathtoGnomesIf it looks like a duck... :p
Instead of making assumptions, maybe try to read up and understand what they've done?
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#11
Chrispy_
I don't understand why the hybrid drives of last decade flopped so badly. The technology they used (MLC and spinning rust) isn't much different to the SLC-mode QLC drives we have today.

I'd love to see an 8TB hard drive with 250GB of NAND running the same way as a QLC drive does - 250GB of fast cache which is written to the platters in the background. The downside would be that IOPS on small reads would be abysmal reading from disk but I'd imagine we're getting closer to file-level awareness in drive firmware that would allow files under 4kb to remain in the cache far longer.
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#12
bug
Chrispy_I don't understand why the hybrid drives of last decade flopped so badly. The technology they used (MLC and spinning rust) isn't much different to the SLC-mode QLC drives we have today.
Going back and forth between SLC and QLC retains NAND's blazing fast seek times. Going back and forth between MLC and spinning rust, doesn't.
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#13
Chrispy_
bugGoing back and forth between SLC and QLC retains NAND's blazing fast seek times. Going back and forth between MLC and spinning rust, doesn't.
Which is why I said:

"The downside would be that IOPS on small reads would be abysmal reading from disk but I'd imagine we're getting closer to file-level awareness in drive firmware that would allow files under 4kb to remain in the cache far longer."

seek times of 15ms aren't a problem for large files. it's the tiny stuff that's always choked spinning rust.
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#14
bug
TheLostSwedeInstead of making assumptions, maybe try to read up and understand what they've done?
What they've done is put out a rather cryptic marketing announcement, which usually means there are little technical aspects to brag about. So it's probably a souped up SSHD.
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#15
Chaitanya
bugWhat they've done is put out a rather cryptic marketing announcement, which usually means there are little technical aspects to brag about. So it's probably a souped up SSHD.
There is a link to tech briefing on this page below. Not sure why it took only 7 days to post PR here without the associated tech briefing.
blog.westerndigital.com/optinand/
TheLostSwedeThat's not what other sites have reported. It literally says "Unlike a hybrid drive where flash is used to store user data" in the press release above.
These drives still have a cache, it's just not part of the iNAND.

www.anandtech.com/show/16920/western-digital-reimagines-hdd-flash-integration-with-optinand


And this has what to do with the product announcement above?
This is an ePMR drive.


Possibly, considering the metadata is stored in the flash. I guess it would be tricky to recover at least some data without it.


Instead of making assumptions, maybe try to read up and understand what they've done?
Wont take long for WD to pull similar stunt with this format and blame customers for using too much storage drive.
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#16
TheLostSwede
bugWhat they've done is put out a rather cryptic marketing announcement, which usually means there are little technical aspects to brag about. So it's probably a souped up SSHD.
There's nothing cryptic about it and if you don't understand the press release, read the link to Anandtech where they break it down.
The iNAND is not used for file buffering of any kind.
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#17
bug
TheLostSwedeThere's nothing cryptic about it and if you don't understand the press release, read the link to Anandtech where they break it down.
The iNAND is not used for file buffering of any kind.
The marketing statement relayed here on TPU is cryptic, in that it does little to explain how this all works. I can see there's a bit more info in the tech briefs, I'll have to take a closer look at those.
So far, I got that the flash stores some metadata that cuts down the number of sector refreshes needed. I don't see how that alone would increase capacity, for example, so there has to be more.
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#18
TheLostSwede
bugThe marketing statement relayed here on TPU is cryptic, in that it does little to explain how this all works. I can see there's a bit more info in the tech briefs, I'll have to take a closer look at those.
So far, I got that the flash stores some metadata that cuts down the number of sector refreshes needed. I don't see how that alone would increase capacity, for example, so there has to be more.
It gives you increased capacity, because said metadata is no longer stored on the platters, but inside the iNAND.
I would say that they've played up the increased capacity due to the metadata being taken off the platters, but in all honesty, I don't know how much metadata there is on a hard drive.
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#19
Punkenjoy
TheLostSwedeIt gives you increased capacity, because said metadata is no longer stored on the platters, but inside the iNAND.
I would say that they've played up the increased capacity due to the metadata being taken off the platters, but in all honesty, I don't know how much metadata there is on a hard drive.
It's not the amount of Metadata now stored on the flash that increase the drive capacity but what they do with it. From my understanding, they pack more tightly the data on the plate and they need to refresh adjacent data more frequently. They say from one time per 1000 writes to one time per 6 writes to adjacent track. They need to then track write per track.

But also, on modern drive, Drive virtualize the cylinder and sectors data. Metadata will store all the actual location of each bytes on the platters. The larger the disk, the larger those table become.
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#20
InVasMani
I'm somewhat surprised DRAM on HDD's hasn't been replaced with Optane. Perhaps the cost to capacity relative to performance isn't suitable enough though. It kind of seems like the cache on HDD's have to be a bit restrained by the interface itself as well I mean seeing as the I-RAM was so why wouldn't the DRAM cache with a SATA/SAS HDD be in turn?
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#21
Crackong
TheLostSwedeThat's not what other sites have reported. It literally says "Unlike a hybrid drive where flash is used to store user data" in the press release above.
These drives still have a cache, it's just not part of the iNAND.
Isn't that just a marketing term as usual from WD, from what they have described, it is exactly a SSHD, just with a little tweak of how they are using the NAND part of it not purely for storage cache.
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#22
chodaboy19
The NAND is used internally by the HDD controller to track each sector. WD has a better explanation of it all: documents.westerndigital.com/content/dam/doc-library/en_us/assets/public/western-digital/collateral/tech-brief/tech-brief-reimagining-hdds-with-optinand-technology.pdf
Write operations are recorded to reduce adjacent track interference (ATI). In prior generation HDDs, write operations were recorded at the track level, while refreshes were done for entire tracks. OptiNAND records write operations in iNAND at the sector level. This metadata is used to refresh sectors instead of whole tracks. Eliminating excess refreshes allows tracks to be placed closer together without performance loss.
“It used to be, not that many generations ago, that you could write 10,000 times before needing to refresh sectors on either side,” Hall said. “And then as we pushed the tracks closer and closer together, it went to 100 then 50 then 10, and now for some sectors, it’s as low as six.”
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#23
Andy Shiekh
Why did Western Digital abandon the hybrid hard drive in the first place?
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#24
claes
I know you love SSHDs but they are garbage. Get an actual SSD, rather than some hodgepodge experimental permutation of two well studied technologies, and you’ll understand. The latency on SSHDs is trash, which is the whole argument SSDs make. Even WD acknowledges this with their new “NAND assisted drives” — the only real thing NAND can do for a HDD is store the bitmap and run ECC.

*im drunk and may have mischaracterized these technologies but, still, case in point
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#25
Andy Shiekh
claesI know you love SSHDs but they are garbage. Get an actual SSD, rather than some hodgepodge experimental permutation of two well studied technologies, and you’ll understand. The latency on SSHDs is trash, which is the whole argument SSDs make. Even WD acknowledges this with their new “NAND assisted drives” — the only real thing NAND can do for a HDD is store the bitmap and run ECC.

*im drunk and may have mischaracterized these technologies but, still, case in point
Better tell that to Apple with their fusion drive.
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