SanDisk's Extreme II, the neopolitan SSD

Subject: Storage | July 15, 2013 - 04:05 PM |
Tagged: sandisk, Extreme II series, ssd, mlc, slc

SanDisk has done something interesting with their new Extreme II SSD series, they have used both SLC and MLC flash in the drive to attempt to give users the best of both worlds.  The drive still has a DDR cache sitting between the flash storage and the controller, but there is an nCache between the MLC flash and the DDR comprised of ~1GB of SLC flash.  The idea is that the SLC can quickly accumulate a number of small writes into a larger single write block which can then be passed to the MLC flash for storage.  Don't think of it as a traditional cache in which entire programs are stored for quick access but more as a write buffer which fills up and then passes its self to the long term storage media once it is full.  The Tech Report put this drive through their tests and found it to be a great all around performer, not the fastest nor the best value but very good in almost any usage scenario.

TR_ncache.jpg

"With MLC main storage and an SLC flash cache, the SanDisk Extreme II is unlike any other SSD we've encountered. We explore the drive's unique design and see whether it can keep up with the fastest SSDs on the market."

Here are some more Storage reviews from around the web:

Storage

SanDisk pairs Marvell and MLC in their new Extreme II series

Subject: Storage | June 7, 2013 - 06:38 PM |
Tagged: sandisk, Extreme II series, marvell 9187, 19nm, mlc

SanDisk claims their Extreme II can run at 550/510 MB/s sequential read/write, and 95,000/78,000 for random read/write IOPS, a claim which [H]ard|OCP just put to the test.  The two major changes to this drive that will contribute to the difference in speed are the switch from a Sandforce controller to the Marvell 9187 controller and the MLC flash which is 19nm in this drive.  Testing shows that the drive does live up to expectations though they did point out the lack of encryption as a weakness.  Prices for the drives are around the magic $1/GB mark, making this drive a solid contender in a very populous market.

sanex2.jpg

"SanDisk releases its Extreme II series SSD, which features the Marvell 9187 controller in concert with 19nm eX2 ABL MLC NAND. The competition is heating up as another manufacturer with massive foundry capabilities releases a new SSD. Will the Extreme II "blaze through your day" and "keep you ahead of deadlines?"

Here are some more Storage reviews from around the web:

Storage

Source: [H]ard|OCP

Crucial's inexpensive M500 makes MLC NAND affordable

Subject: Storage | May 28, 2013 - 01:47 PM |
Tagged: ssd, crucial m500, mlc, marvell 9187, RAIN

Before discussing the impressive price point of Crucial's M500 drive their are two features worth mentioning about this drive, RAIN and the Marvell 9187 controller.  RAIN is Redundant Array of Independent NAND which offers data parity which will allow you to successfully recreate data after an uncorrectable error, something which might put the minds of those still leery of SSDs to rest.  The new Marvell controller is the secret to the pricing of this drive, it allows the usage of 128Gbit (16GB) NAND dies as opposed to the more common 64GBit dies and is produced at a lower cost than other controllers.  [H]ard|OCP tested the 512GB drive and does warn that the specifications of the two smaller capacity drives are different enough to require individual testing.  However as you can pick up the 512GB drive for $400 you might simply opt for the largest drive which offers competitive performance at an amazing $0.78/GB.

H_m500.jpg

"Crucial's M500 offers the lowest price per gigabyte for an MLC SSD with enterprise-class features not seen on typical consumer SSD data drives. With new 128Gbit MLC NAND paired with the Marvell 9187 controller the M500 should deliver great performance at a historically low price point. Is the Crucial M500's performance up to par?"

Here are some more Storage reviews from around the web:

Storage

Source: [H]ard|OCP

Micron puts a suit and tie on its newest PCIe SSD

Subject: General Tech | May 3, 2013 - 12:38 PM |
Tagged: micron, PCIe SSD, P420m, 25nm, mlc

Soon to be available in 350GB, 700GB and 1.4TB capacities, the Micron P420m PCIe SSD will be in a half-height and half-length form factor perfect for use in racks.  DigiTimes mentions it will use a custom ASIC controller from Micron but does not specify the model.  As will it will use 25nm MLC flash and XPERT, which is Micron's eXtended Performance and Enhanced Reliability Technology which should guarantee a decent lifespan for your storage.  Production will not start until June so it will be a while before we finally see performance results.

micron-p420.jpg

"The new Micron P420m combines consistent performance with the inherent power efficiency of an all-flash system to deliver improved economics for enterprise data centers. The drive accelerates performance of today's demanding data center applications, including online transaction processing (OLTP), data warehousing and virtualization, Micron said."

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Tech Talk

Source: DigiTimes

New Flash based products coming to a server near you

Subject: General Tech | April 4, 2013 - 01:40 PM |
Tagged: memristor, non-volitle RAM, mlc, PCIe SSD, hitachi, hp, dell

The Register assembled a brief look at the near future of flash storage products from HP, Hitachi, Dell and NetApp.  HP expects to be shipping memristor based storage devices by the end of the year as well as photonic inter-node backplanes which will offer much faster transfer than copper based solutions.  Hitachi Data Systems believes they have made a breakthrough in MLC flash and controller technology which will not only extend the usable life of the memory but they expect price parity with high end SAS HDDs by the end of 2015.  Check out those stories as well as Dell's server plans and NetApp's new OS right here.

rcjMemristor.jpg

"In every minute;

  • More than 600 videos are uploaded to YouTube
  • More than 13,000 hours of music are streamed via Pandora
  • 168 million emails are transmitted
  • 695,000 status updates are added to Facebook
  • 695,000 Google searches are also made."

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Tech Talk

Source: The Register
Subject: Editorial, Storage
Manufacturer: Various
Tagged: tlc, ssd, slc, mlc, endurance

Taking an Accurate Look at SSD Write Endurance

Last year, I posted a rebuttal to a paper describing the future of flash memory as ‘bleak’. The paper went through great (and convoluted) lengths to paint a tragic picture of flash memory endurance moving forward. Yesterday a newer paper hit Slashdotthis one doing just the opposite, and going as far as to assume production flash memory handling up to 1 Million erase cycles. You’d think that since I’m constantly pushing flash memory as a viable, reliable, and super-fast successor to Hard Disks (aka 'Spinning Rust'), that I’d just sit back on this one and let it fly. After all, it helps make my argument! Well, I can’t, because if there are errors published on a topic so important to me, it’s in the interest of journalistic integrity that I must now post an equal and opposite rebuttal to this one – even if it works against my case.

First I’m going to invite you to read through the paper in question. After doing so, I’m now going to pick it apart. Unfortunately I’m crunched for time today, so I’m going to reduce my dissertation into the form of some simple bulleted points:

  • Max data write speed did not take into account 8/10 encoding, meaning 6Gb/sec = 600MB/sec, not 750MB/sec.
  • The flash *page* size (8KB) and block sizes (2MB) chosen more closely resemble that of MLC parts (not SLC – see below for why this is important).
  • The paper makes no reference to Write Amplification.

Perhaps the most glaring and significant is that all of the formulas, while correct, fail to consider the most important factor when dealing with flash memory writes – Write Amplification.

Before geting into it, I'll reference the excellent graphic that Anand put in his SSD Relapse piece:

writeamplification2.png

SSD controllers combine smaller writes into larger ones in an attempt to speed up the effective write speed. This falls flat once all flash blocks have been written to at least once. From that point forward, the SSD must play musical chairs with the data on each and every small write. In a bad case, a single 4KB write turns into a 2MB write. For that example, Write Amplification would be a factor of 500, meaning the flash memory is cycled at 500x the rate calculated in the paper. Sure that’s an extreme example, but the point is that without referencing amplification at all, it is assumed to be a factor of 1, which would only be the case if you were only writing 2MB blocks of data to the SSD. This is almost never the case, regardless of Operating System.

After posters on Slashdot called out the author on his assumptions of rated P/E cycles, he went back and added two links to justify his figures. The problem is that the first links to a 2005 data sheet for 90nm SLC flash. Samsung’s 90nm flash was 1Gb per die (128MB). The packages were available with up to 4 dies each, and scaling up to a typical 16-chip SSD, that only gives you an 8GB SSD. Not very practical. That’s not to say 100k is an inaccurate figure for SLC endurance. It’s just a really bad reference to use is all. Here's a better one from the Flash Memory Summit a couple of years back:

flash-1.png

The second link was a 2008 PR blast from Micron, based on their proposed pushing of the 34nm process to its limits. “One Million Write Cycles” was nothing more than a tag line for an achievement accomplished in a lab under ideal conditions. That figure was never reached in anything you could actually buy in a SATA SSD. A better reference would be from that same presentation at the Summit:

flash-2.png

This shows larger process nodes hitting even beyond 1 million cycles (given sufficient additional error bits used for error correction), but remember it has to be something that is available and in a usable capacity to be practical for real world use, and that’s just not the case for the flash in the above chart.

At the end of the day, manufacturers must balance cost, capacity, and longevity. This forces a push towards smaller processes (for more capacity per cost), with the limit being how much endurance they are willing to give up in the process. In the end they choose based on what the customer needs. Enterprise use leans towards SLC or eMLC, as they are willing to spend more for the gain in endurance. Typical PC users get standard MLC and now even TLC, which are *good enough* for that application. It's worth noting that most SSD failures are not due to burning out all of the available flash P/E cycles. The vast majority are due to infant mortality failures of the controller or even due to buggy firmware. I've never written enough to any single consumer SSD (in normal operation) to wear out all of the flash. The closest I've come to a flash-related failure was when I had an ioDrive fail during testing by excessive heat causing a solder pad to lift on one of the flash chips.

All of this said, I’d love to see a revisit to the author’s well-structured paper – only based on the corrected assumptions I’ve outlined above. *That* is the type of paper I would reference when attempting to make *accurate* arguments for SSD endurance.

OCZ Technology Delivers Vertex 3 with 20 Nanometer Flash

Subject: Storage | February 19, 2013 - 02:47 PM |
Tagged: ocz, vertex 3, 20nm, mlc

SAN JOSE, CA—February 19, 2012—OCZ Technology Group, Inc. (Nasdaq:OCZ), a leading provider of high-performance solid-state drives (SSDs) for computing devices and systems, today announced a new 20 nanometer (nm) NAND flash version of its award-winning Vertex 3 SSD Series. The new Vertex 3.20 SSD is a 2.5-inch, 6Gbps SATA III-based Multi-Level Cell (MLC) drive that implements the feature-set of the Vertex 3 Series but is built around smaller, state-of-the-art NAND flash process geometry.

Being that the Vertex 3 Series is one of OCZ’s most popular SSDs to date, and has received numerous accolades from media reviewers globally, the implementation of 20nm NAND flash will extend its availability and enable mainstream users of mobile and desktop platforms to improve gaming, multimedia, and the overall computing experience over traditional hard disk drives (HDDs) and other competing SSDs. The Vertex 3.20 SSD will be available in 120GB and 240GB storage capacities, with 480GB capacities to follow soon.

Utilizing the proven and effective LSI SandForce® SF-2200 processor, the Vertex 3.20 SSD delivers exceptional performance of synchronous 20nm NAND flash supporting read bandwidth up to 550MB/s, write bandwidth up to 520MB/s, random read performance up to 35,000 input/output operations per second (IOPS), and random write performance up to 65,000 IOPS. It is also optimized to provide excellent endurance and reliability coupled with power efficiency.

“OCZ is always looking for ways to deliver superior solid state drive storage performance and features, as well as making this technology more accessible to the complete range of customers,” said Daryl Lang, Senior Vice President of Product Management for OCZ Technology. “The Vertex 3 has been a popular SSD series among consumers and implementing the newer, smaller process geometry will not only extend its life, but enables mainstream users with an excellent computing experience at a competitive price point.”

The Vertex 3.20 SSD is supported by a 3-year warranty to ensure customer satisfaction and will be available shortly through OCZ’s global channel in 120GB and 240GB storage capacities.

Vertex3_20.jpg

Revisit the Vector, it is worth it

Subject: Storage | February 15, 2013 - 04:26 PM |
Tagged: vector, ssd, sata, ocz, mlc, Indilinx Barefoot

Just in case you forgot how impressive the OCZ Vector 256GB is, Overclockers Club would like to remind you.  The Indilinx Barefoot 3 controller is matched with low cost 25nm MLC IMFT NAND modules and 512MB of DDR3-1600 RAM for a cache.  That translates to incredibly fast performance but without the high price of other drives.  The 256GB model sits currently just under $1/GB, it is not the least expensive SSD available but when you consider the speeds this drive operates at it is the best value.  Remind yourself where OCZ's Vector sits in the pack by reading on at OCC.

barefoot3_diagram-mod.png

"OCZ's Vector line of solid state drives is every bit the performer that the Vertex 4 drives are with very few exceptions. In many of the tests, the two fastest drives were the Vertex 4 and OCZ's latest Indilinx Barefoot 3-equipped Vector. The only real weakness I saw was that the Vector was less frugal with the CPU cycles than the other Indilinx equipped drives. OCZ's move to the Barefoot 3 controller is beginning to pay dividends as it uses the technologies it has available in-house after the Indilinx and PLX acquisitions. It's taken a while to go all-in but that time has come. As the first totally in-house designed controller from OCZ, it seems to have hit on a controller that does better at managing real world usage scenarios and handling both compressible and incompressible data streams.”

Here are some more Storage reviews from around the web:

Storage

Intel Launches New 335 Series SSD In 180GB Capacity

Subject: Storage | February 5, 2013 - 03:16 AM |
Tagged: ssd, SandForce SF-2281, sandforce, mlc, intel 335, Intel

Intel has added a new drive to its existing 335 SSD series. The new drive offers up 180GB of storage, but maintains the same level of read and write performance as its larger 240GB sibling.

Intel 335 Series 180GB SSD.jpg

The 180GB version uses 20nm MLC NAND flash paired with a SandForce SF-2281 controller. According to the Intel-provided spec sheet (PDF), the new drive is capable of sustained read and write speeds of 500 MB/s and 450 MB/s respectively. Further, the drive maxes out at 42,000 random read IOPS and 52,000 random write IOPS.

The drive will come in the 2.5” form factor, but is 9.5mm thick (meaning it will not work in all notebooks). Reportedly, Intel has redesigned the casing to include a schematic/blueprint graphic alongside the Intel logo.

Intel rates the 180GB 335 series SSD at 1.2 million MTBF and is warranted for three years. The drive can currently be found online for around $180, making it right around the $1/GB mark. Interestingly, the larger 240GB model is currently retailing for around $195. Therefore, if you can spare the extra $15, the 240GB model is the better deal.

Source: Intel

Kingston updates their SSDNow lineup

Subject: Storage | February 4, 2013 - 02:09 PM |
Tagged: kingston, ssdnow v300, SF-2281 controller, mlc

Kingston's updated SSDNow V300 uses 19nm Toshiba Toggle NAND and the SandForce 2281 controller with some unspecified enhancements.  Kingston has made a name for themselves in the SSD market for offering an easy and fully explained upgrade path for users who are unfamiliar with changing hard drives.  The updated version is no different, included is an external enclosure for the SSD and a USB cable to allow users to easily copy over any data which is of great benefit for users who don't have several enclosures laying around.  [H]ard|OCP's testing showed that even though this is a value priced drive, it also performs better than a lot of the competition.

H_kingstonssdnow.jpg

"The Kingston SSDNow V300 is yet another value-oriented SSD in Kingston's wildly successful line of mainstream solid state drives. With the pressures of TLC SSDs squeezing the value market we take a look and see if a standard MLC SSD with 19nm Toshiba Toggle NAND and an SF-2281 processor can keep up with the changing times."

Here are some more Storage reviews from around the web:

Storage

Source: [H]ard|OCP