SSD

SanDisk to Acquire SMART Storage

The following is excerpted from an Objective Analysis Alert e-mailed to our clients on 2 July, 2013:

SanDisk to Acquire SMART Storage SystemsSanDisk Corporation announced on 2 July 2013 an agreement to acquire SMART Storage Systems, the SSD arm of SMART Modular Technologies, for $307 million in cash and equity. The transaction is expected to close in August, 2013.

SMART has strong SSD technology that allows the company to ship MLC-based SSDs with endurance specifications superior to those of some SLC SSDs.  The SSD maker had shipments of about $25M in its most recent quarter.

The SMART acquisition will be the fourth 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

WDC’s HGST Intros 12G SAS MLC SSDs

Latencey Histogram of HGST's MLC SSDIn case you didn’t have enough abbreviations in your life, The SSD Guy brings you the headline above, with the promise that the news below is really interesting: HGST (formerly Hitachi Global Storage Technology, but now a division of WDC – Western Digital Corp.) has brought out a new line of 12Gb/s SAS SSDs based on MLC flash.  These are a part of the UltraStar line.

Whereas HGST’s first-generation UltraStar SAS SSDs used SLC flash, the new SSDs are based on 25nm MLC flash but offer the same warranties as HGST’s prior generation.  Even so, performance for the new SSDs is significantly faster than that of their SLC-based predecessors, with no reduction in wear or lifetime specifications.

These SSDs are the first to support Continue reading

Are HDDs Vibration Sensitive?

Brendan Gregg in Sun's Fishworks Lab shouting at an HDD arrayOne reason to use SSDs is that, with no moving parts, these devices are insensitive to shock and vibration.  HDDs, on the other hand, are sensitive enough to vibration that it can cause access delays.

How sensitive are they?  Well, I have seen some overblown claims from SSD makers that shock will cause HDD head crashes.  I am not sure that I believe such claims, but I certainly do believe that an HDD’s actuator (the read/write head mechanism) can be shaken away from its track, causing a Continue reading

SSDs and TCO

Shed some light on your SSD decisionOne of the best arguments to use an SSD is also one of the most difficult ways to sell anything.  This is the Total Cost of Ownership, commonly abbreviated to “TCO.”

TCO has been used as an argument for buying anything from compact fluorescent bulbs to Jaguar automobiles.

The argument usually revolves around an item whose initial price is higher, but which has lower ongoing (or operating) costs, and when these costs are combined, the higher-priced item proves to cost less to own over the long run.  In the case of a compact fluorescent (CF) bulb, the bulb may cost $7, versus $1 for an incandescent bulb, but it consumes 18 Watts compared to the 75 Watts consumed by the incandescent bulb it replaces.  In addition the CF bulb lasts ten times as long (10,000 hours vs. 1,000 hours.)  This works out to a savings of 470 kWh – or about $50 – plus $3 in bulb costs. Continue reading

Extreme SSD Error Correction

Chuo University EmblemAt last week’s International Solid State Circuits Conference (ISSCC) Shuhei Tanakamaru, a researcher from Japan’s Chuo University, detailed a scheme to reduce MLC SSD bit error rates (BER) by 32 times over conventional techniques.  The approach used an impressive combination of mirroring, vertical and horizontal error correction, and a deep understanding of the most likely kinds of bit errors flash will experience.

This is a very novel and well-conceived technique that may find industry adoption in future SSDs.

The steps included in the paper are used in addition to the Continue reading

How Controllers Maximize SSD Life – Internal NAND Management

Tempus FugitGiven that you have used all those other forms of improving SSD wear that we have discussed so far, but you still don’t find that this is enough, what do you do next?  Well a few SSD controllers go one step further and manage some of the inner workings of the NAND flash chip itself.

If that sounds like a significant undertaking to you, then you clearly understand why so very few controllers take this approach.  The information used to perform this function is not generally available – it takes a special relationship with the NAND flash supplier – and you can’t develop this relationship unless the NAND supplier Continue reading

How Controllers Maximize SSD Life – Feedback on Block Wear

Tempus FugitOne way that SSD controllers maximize the life of an SSD is to use feedback on the life of flash blocks to determine how wear has impacted them.  Although this used to be very uncommon, it is now being incorporated into a number of controllers.

Here’s what this is all about: Everybody knows that endurance specifications tell how much life there is in a block, right?  For SLC it is typically 100,000 erase/write cycles, and for MLC it can be as high as 10,000 cycles (for older processes) but goes down to 5,000 or even 3,000 for newer processes.  TLC endurance can be in the hundreds of cycles.  Now the question is: “What happens after that?”

In most cases individual bits start to 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

How Controllers Maximize SSD Life – Over Provisioning

Tempus FugitOver provisioning is one of the most common ways that SSD designers can help assure that an SSD has a longer life than the flash’s endurance rating would support.  If an SSD contains more flash than is presented at its interface, the controller can manage wear across a larger number of blocks while at the same time accelerating disk performance by moving slow operations like block erases out of the way of the SSD’s key functions.

Many people like to compare wear leveling to rotating a car’s tires.  In this vein, think of over provisioning as having a bunch of spare Continue reading

Contact

Jim Handy
Objective Analysis
SSD Market Research
+1 (408) 356-2549
Jim.Handy (at) Objective-Analysis.com

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