NAND

MLC vs. eMLC – What’s the Difference?

eMLCFrom time to time IT managers ask The SSD Guy if there’s an easy way to compare SSDs made with MLC flash against those made using eMLC flash.  Most folks understand that eMLC flash is a less costly alternative to SLC flash, both of which provide longer wear than standard MLC flash, but not everyone realizes that eMLC’s superior endurance comes at the cost of slower write speed.  By writing to the flash more gently the technology can be made to last considerably longer.

So how do you compare the two?  OCZ introduced MLC and eMLC versions of the same SSD this week, and this provides a beautiful opportunity to explore the difference.

As you would expect, the read parameters are all identical.  This stands to reason, since Continue reading

IBM to Invest $1B in Flash Promotion

The following is excerpted from an Objective Analysis Brief e-mailed to our clients on 15 April, 2013:

Comparison of 3-Year Operating Costs: Flash vs HDD (Wikibon)On April 11 IBM kicked off “The IBM Flash Ahead Initiative”, committing to spend more than $1 billion for flash systems and software R&D and to open twelve IBM Flash Centers of Competency around the world staffed with flash experts armed with flash systems to help clients test drive flash in their own situations.

This follows from IBM’s August 2012 agreement to acquire privately-held Texas Memory Systems (TMS), a very low profile manufacturer of high-performance flash-based memory arrays and PCIe SSDs. TMS is the world’s oldest SSD maker, founded in 1976, to manufacture RAM-based replicas of HDDs. About four years ago TMS used its Continue reading

19nm & 20nm SSDs Arrive!

Toshiba 19nm vs. IMFT 20nm NAND Processes (Courtesey Techinsights and Toshiba)SSD-watchers have expressed some concern over the last few years that  SSDs cannot be manufactured using advanced NAND flash process geometries.  This is because these parts have lower endurance and a larger number of bit errors than NAND made using less-advanced processes – the tighter the process, the shorter the flash’s life, and the more errors it will have.

Fortunately these concerns seem to be Continue reading

IBM Completes Texas Memory Systems Acquisition

IBM Acquires Texas Memory Systems (TMS)IBM announced on Monday October 1 that it had finalized its acquisition of Texas Memory Systems (TMS.)  This transaction was first announced in mid-August and was analyzed at that time in an Alert sent to Objective Analysis clients.

Here are a few salient points from the Alert:

  • TMS is the world’s oldest SSD maker, and has recently made an aggressive move from DRAM to NAND flash, providing very high performance PCIe SSDs and arrays.
  • TMS and IBM play into the same market: storage for large-scale computing.  Their technologies complement each other, since IBM’s current solid state storage offerings were lightweight compared to those of TMS.
  • The acquisition meshes with IBM’s mantra of “Smarter Planet, Smarter Storage, and Smarter Computing.”  SSDs improve storage speed while reducing power and space requirements.

Objective Analysis sees this as a good fit that will harness the synergies of two very similarly managed companies to produce very positive results.

 

For the Lack of a Fab…

SanDisk-Toshiba Yokkaichi Plant from WD 2007 IDEMA PresentationOne popular argument to explain why SSDs have not displaced the HDDs in all PCs is that there isn’t enough NAND flash production capacity to support this business and there never can be.

This argument has been posed as long ago as 2007 by WD CEO John Coyne at an IDEMA conference (the source of this post’s graphic), SanDisk’s Eli Harari at the Flash Memory Summit in 2008, and Seagate‘s CEO Steve Luczo in a Forbes interview as recently as last April.  These are captains of the industry.  Their arguments make people stand up and take notice.

It’s a really flawed argument.

It goes like this: Continue reading

An ReRAM SSD Design

Chuo University EmblemA colleague pointed The SSD Guy to an ExtremeTech article about researchers at Japan’s Chuo University who have designed an SSD that uses a resistive RAM (ReRAM) as a buffer and is built using TSV technology.  The design was presented at the IEEE’s 2012 Symposium on VLSI Circuits this month in Hawaii.  A Nikkei article gives additional information.

The basic architecture reminds me of an FRAM + NAND SSD design that a Korean university presented at the Flash Memory Summit a few years ago.  Either approach gets past the problem of using a failure-prone battery, a temperature-sensitive supercap, or a big bulky bank of Continue reading

Toshiba Reveals Hybrid HDD Research

Hybrid HDD - An HDD with a NAND Flash CacheNikkei Electronics published an article on May 22 detailing a May 17 briefing by Toshiba president Norio Sasaki. Mr. Sasaki told of the company’s plans to introduce a hybrid HDD (HHDD) in September of this year that is aimed at the Ultrabook market. The article notes that Toshiba is the only company that produces both NAND flash and HDDs, now that Samsung sold its HDD business to Seagate.

The article also says that Toshiba: “aims to become one of the top three companies in the HDD market in terms of market share.” The SSD Guy is forced to wonder at this comment, since there are only three HDD manufacturers in existence today: Toshiba, Western Digital, and Seagate.

The Seagate Momentus XT, the only Continue reading

DensBits Debuts with eMMC Controller

DensBits Promises Higher Performance While Reducing CostDensBits, a flash memory controller company, has just introduced its new DB3610 “Memory Modem” eMMC controller for 3-bit or TLC flash.  The controller is the first to use DensBits’ new technology which the company claims can coax better reliability out of 3-bit flash than most controllers can out of 2-bit MLC, to provide important cost savings to OEMs.

Read and write performance is also said to be nearly on a par with 2-bit MLC.

DensBits’ Memory Modem is a blend of Continue reading

Western Digital CEO: Hybrid Drives “Strategic”

Hybrid HDD - An HDD with a NAND Flash CacheDuring Western Digital’s April 26 earnings call (as transcribed by Seeking Alpha) CEO John Coyne disclosed that Western Digital has ongoing development efforts in hybrid HDDs: “In addition, we are continuing investments in strategic growth areas such as SSD, hybrid drives and the digital home.”

It’s encouraging to see a second entrant into this market.

After a false start that was synchronized with the ill-fated launch of Microsoft’s Vista operating system, hybrid HDDs have been a technology that is rarely ever mentioned.  So far the hybrid HDD has been the sole domain of Seagate Technology with Continue reading

Victorinox’ Terabyte-in-Your-Pocket

Victorinox 1TB SSDAt The Consumer Electronics Show this week, Swiss army knife maker Victorinox introduced a one-terabyte SSD in a form factor similar to a fat Swiss army knife.  Yes, that is right – a terabyte of NAND flash in your pocket.  The company tells us that the device’s dimensions, including the connector, are a scant 52x18x10mm.

Some of the other features include the use of an eSATA connector (to allow the product to be plugged into either a SATA port or a USB socket), AES256 encryption (any army would like this), and a bi-stable LCD to tell how much free space remains on the device.

But let’s look at the difficulty of building a 1TB flash SSD in such a small space:

Continue reading