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   Technology StocksWDC, NAND, NVM, enterprise storage systems, etc.


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From: Bruno Cipolla8/4/2021 4:49:47 AM
   of 4711
 
Kioxia Demos HLC 3D NAND and Talks About OLC NAND
By Anton Shilov 7 days ago

Six or even eight bits per cell might be coming, eventually

Comments (3)



(Image credit: Kioxia)

The best SSDs currently use TLC or maybe QLC memory. Kioxia (formerly Toshiba Memory) was the first 3D NAND maker to start talking about 5-bits-per-cell (5 bpc) PLC (penta level cell) 3D NAND memory back in 2019. Kioxia's scientists and engineers certainly don't want to rest on their laurels, and this year they demonstrated operation of 6 bpc — hexa level cell, or HLC — 3D NAND memory and believe that even 8 bpc — octa level cell, or OLD — 3D NAND is possible. But there are some important nuances.

To store more than one bit per cell, NAND memory has to hold multiple distinct voltage levels in that cell. For example, MLC has four states per cell, TLC uses eight voltage levels, QLC has 16 voltage levels, and PLC has 32 voltage states. In other words, two taken to the power of whatever cell level you're talking about. To store six bits per cell (HLC), that cell has to hold 2^6, or 64 voltage levels.

To build 3D NAND with such cells, manufacturers have to overcome multiple challenges. They have to find the right materials that can handle storing 64 different voltage states, while also being able to differentiate between those states. That's means the voltage states can't interfere with each other. Keeping temperatures in check is also important and becomes increasingly difficult at higher bits per cell.

To demonstrate the possibility of HLC memory, Kioxia's scientists took one of the company's existing 3D NAND memory chips and immersed it in liquid nitrogen (77K, -196°C) to eliminate deterioration of the cells caused by rewrite cycles. The extremely low temperatures also help to reduce the need for tunnel insulating films, lower the voltage requirements, and stabilize the materials. All together, this improves the physical properties and processes that take place in the IC.

Kioxia's scientists said that they not only managed to write and read six bits of data from one cell and reliably hold it for 100 minutes, but they also were able to achieve a 1,000 program/erase (P/E) cycles endurance. Of course, that's largely thanks to the -196C temperatures. In normal conditions, endurance of 3D HLC NAND memory would be around 100 P/E cycles, according to its estimates. Kioxia presented results of the experiment at the 5th IEEE Electron Devices Technology and Manufacturing Conference (EDTM 2021) in April 2021 (presentation number: WE2P4-5), reports PC Watch.

3D PLC NAND has not been commercialized yet, and Western Digital (Kioxia's manufacturing partner) believes it will only make sense for some SSDs after 2025. Western Digital further claims that 3D PLC brings too many issues for a mere 25% density increase.

In contrast, 3D HLC NAND increases flash memory density by 50% compared to 3D QLC NAND, so it's more likely to be commercially feasible. Furthermore, scientists from Kioxia believe that even eight bits per cell OLC 3D NAND with 256 voltage levels is technologically possible. The task for scientists and developers now is to find the right materials, design, and controllers to make 3D HLC and 3D OLC NAND operational and commercially feasible at room temperatures.

If they fail, development of multi-level cell 3D NAND will stop at PLC and makers of flash will have to focus on increasing the number of layers in 3D NAND flash to increase memory density. Granted, Samsung and SK Hynix believe that 600 to 1,000 layers are feasible, which already opens the doors to very high capacity SSDs.

Even if Kioxia's scientists succeed in making HLC and OLC NAND work at room temperatures, they will also have to develop appropriate controllers that will be able to reliably read and write data from such flash memory. Such controllers will have to support extremely complex ECC algorithms that will require significant compute horsepower. Will such controllers be too expensive and offset the capacity advantages of 3D HLC and 3D OLC NAND? And what sort of performance could future HLC drives even offer? We already know that even QLC drives tend to perform rather poorly in heavier use cases. Only time will tell, but we don't expect TLC to fade away any time soon.

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From: Sam8/4/2021 6:19:10 PM
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After getting sold immediately the release, the stock is now more or less flat AH. I didn't listen to the CC, so I don't have a clue about what is happening with it. I'll try to read a transcript later tonight or tomorrow. It looks like a great report at first glance!

Western Digital Stock Is Slipping. Earnings Were a Blowout. -- Barrons.com
DOW JONES & COMPANY, INC. 4:48 PM ET 8/4/2021

Symbol Last Price Change
64.94 -1.2 (-1.8143%)
QUOTES AS OF 04:00:00 PM ET 08/04/2021
Eric J. Savitz

Western Digital (WDC) stock is trading lower late Wednesday despite reporting better-than-expected results for the fiscal fourth quarter ended June 30, and providing strong guidance for the September quarter.

For the quarter, Western Digital(WDC) posted revenue of $4.9 billion, up 19% from a year ago, and well above the Street consensus forecast at $4.5 billion. The maker of disk drives and flash memory posted non-GAAP profits of $2.16 a share, ahead of the Street estimate for $1.49 a share, and up from $1.02 a share a year earlier. Under generally accepted accounting principles, the company earned $1.97 a share, up from 63 cents a year earlier. Non-GAAP gross margin expanded to 32.9%, from 27.7% a year earlier, on stronger pricing.

The company said client-devices revenue was up 13% from a year ago, and 8% sequentially, to $2.2 billion, driven by strong demand for notebook and desktop hard drives. Data-center devices' revenue totaled $1.8 billion, up 6% from a year ago and 44% higher than the March quarter, as enterprise demand picked up. Client solutions revenue was $977 million, up 42% from a year ago, and 10% sequentially, as add-on storage products sold through retail and other channels increased.

For the September quarter, Western Digital(WDC) sees revenue ranging from $4.9 billion to $5.1 billion, with non-GAAP profits of $2.25 to $2.55 a share, and non-GAAP gross margin increasing 33%-35%. Street consensus had called for $4.9 billon in revenue and profits of $2 a share.

"I am extremely proud of the outstanding execution our team exhibited as we achieved another quarter of strong revenue, gross margin and EPS results above expectations," CEO David Goeckeler said in a statement. "Throughout this fiscal year, we successfully delivered both flash and hard drive innovations that are essential building blocks in the acceleration of the data economy....We believe we have the right foundation for success -- the right products, the right customer base, and the unique ability to address two very large and growing markets."

In late trading, Western Digital(WDC) stock is off 2.3%, to $63.42.

Write to Eric J. Savitz at eric.savitz@barrons.com

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To: Sam who wrote (4684)8/4/2021 8:05:42 PM
From: Sam
   of 4711
 
Whoops--
"After getting sold immediately *after* the release..."

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To: Sam who wrote (4684)8/4/2021 8:16:30 PM
From: Elroy
   of 4711
 
It looks like a great report at first glance!

Why?

Annual sales were up 1%.

In the current goldilocks environment, how is this a great report?

I compare to SIMO's Q2, which was up ~65% over last year, and up 20% sequentially, and SIMO's 2021 sales will be up more than 70% over last year.....why are the WDC numbers anything even interesting?

Gross margins are 33% non-Gaap. Is that great?

Operating cash flow was $1.9 billion for the fiscal year. What was Cap Ex?

Sales are forecast to go up about 4% next quarter. Next quarter is the big daddy Q3. Is that up 4% great?

Is WDC gaining share on competition, or what's the great story?

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To: Elroy who wrote (4686)8/4/2021 8:32:49 PM
From: Sam
2 Recommendations   of 4711
 
You are comparing a company that just made $221m of revenue for their quarter with a company that made $4.9b. Although one is a customer of the other, they nonetheless are completely different companies in different sectors that have different characteristics. I haven't read or listened to the CC yet, my comment was based entirely on the article I posted and the fact that they handily beat expectations.

Why do you seem to have a hard on for WDC? Do you go around to other boards and compare SIMO with those stocks as well? It is bizarre.

You really should cut it out. I banned you once for doing this and I will ban you again if you keep doing this.

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To: Sam who wrote (4687)8/4/2021 8:41:08 PM
From: Elroy
   of 4711
 
I'm just curious why WDC's results are "good".

1% annual sales growth seem (to me) bad. In fact, it stinks.

If you think WDC's recent results are good, SIMO's recent results are Godlike. And SIMO is cheaper on valuation than WDC.

WDC is not the leader in a highly competitive industry.
SIMO is the leader in a segment without much competition left.

WDC has massive Cap Ex needs every year.

SIMO has almost zero Cap Ex needs every year.

Yeah, I don't have to compare WDC to SIMO. But in comparing financial numbers, one crushes the other, so I'm curious why many here like the one with the much worse numbers, that's all.

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From: Elroy8/4/2021 8:52:02 PM
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WDC the articles and comments I'm reading say it was a really great quarter, and they handily beat expectations.

I don't follow WDC, but the sales numbers don't say the same thing. They did $4.9 billion last quarter, and expect to do $4.9 - $5.1 billion in the upcoming seasonally strong Q3. So they expect to grow sales about 2% sequentially, give or take 2%.

That stinks, doesn't it?

The tech markets are booming, NAND is booming, no one can get enough product made, prices are rising, and we're coming into the best quarter of the year.

And WDC is going to grow sales by 2%?

I remain curious how this is positive news.

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To: Elroy who wrote (4688)8/4/2021 9:04:26 PM
From: Sam
1 Recommendation   of 4711
 
I think that the fact that there has been little discussion on the board implies that most of us are not all that enamored of WDC.

Nonetheless, the comparison of SIMO to them is a little nuts. They are completely different companies. Different sectors with different characteristics and different challenges.

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To: Elroy who wrote (4688)8/4/2021 9:57:56 PM
From: SiliconAlley
   of 4711
 
WDC has massive Cap Ex needs every year.

You appear to lack a basic understanding of how their Cap Ex is funded, why earnings do not tell the whole story, and why their true margins far exceed that stated in the financials.

Fiscal Year 2021 free cash flow was $1.1B, Last I checked, that exceeds the total revenue of the company you continue to pump. I would respectfully request that you take your pumping to the Yahoo boards.

As for your mantra of "hard drives are dead," the conference call clearly states otherwise.

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To: Sam who wrote (4690)8/4/2021 10:03:24 PM
From: Elroy
   of 4711
 
Nonetheless, the comparison of SIMO to them is a little nuts

It's not that they are similar companies, I'm comparing stellar financial numbers (SIMO) with with fairly average if not disappointing average financial numbers (WDC).

The articles I've read all indicate WDC's Q2 was really good. I'm wondering why the article's authors write this/ Perhaps it's just a comparison of actual results to even worse guidance, I don't know.

Someone indicated WDC may have EPS of $10 over the next four quarters. If that's accurate, then yes, it's pretty cheap, at least we can say that.

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