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| leading the way to the
new storage frontier | |
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SSD history
the SSD design heresies
Memory Defined
Software
can
memory chips be made in the wrong country?
40 years of thinking
about nvm endurance - selective memories |
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| improving the latency and
energy of commodity DRAM using adaptive architecture - a PhD paper |
Editor:- March 13, 2018 - The enterprise flash
SSD market has a long history of design advances which came from the cumulative
understanding gained by the independent characterization of memories - this
mostly having been done by independent SSD and
controller companies
rather than the original manufacturers of the
flash memories
themselves. But I haven't heard much in the past 10 years about similar
activities related to DRAM - and part of the reason may well be that the
companies which used to do such in depth RAM characterizations in earlier phases
of SSD
history - the RAM SSD
companies like Texas Memory Systems and Solid Data Systems - had mostly stopped
design work on new high capacity RAM SSDs by about 2008 due to the competitive
advantages (in a storage array context) of
enterprise flash.
So
I was surprised and delighted to come across a new
report -
Understanding and Improving the
Latency of DRAM-Based Memory Systems (pdf) - by Kevin K. Chang
- Carnegie Mellon University (submitted December 2017 as part his PhD) which
document (in 200 pages approx) describes his ongoing work and insights into
DRAM characterization and system optimization opportunities.
Chang's
research measured and analyzed the relationships between supply voltage and
latency in commodity DRAM and explored ways to optimize latency while still
maintaining data integrity and reducing power consumption. Among several schemes
also described in this paper:-
- an adaptive latency scheme he calls "Flexible-LatencY DRAM (FLY-DRAM)"
which leverages the variation of latency that occurs within different
locailities of DRAM chips.
- Voltron - a new mechanism that improves system energy by dynamically
adjusting the DRAM supply voltage using a new performance model which is based
on a better understanding of the relationships between cell retention, refresh
rate, temperature and other system factors.
...read the article (pdf)
See
also:- what's RAM really? - RAM
in an SSD context | | |
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| Getting to
4 |
Editor:- March 21, 2018 - Re newsletters and
blogs:- Carey Hedges
founder - HN Marketing - told me
22 years ago (when I was starting an ezine called
MarketingViews with tips for
marketers to interface better with readers of my enterprise server
publication which
preceeded StorageSearch) that
most most newsletters (and by inference - in today's world - blogs) rarely make
it past 3 editions.
So this month when I saw Rohit Gupta - Segment
Manager, Enterprise Storage Solutions at SanDisk saying on
linkedin - "My 4th blog- NVMe Part II" - about his -
Deep
Dive - 6 NVMe Features for Enterprise & Edge Storage - I was reminded
of that earlier 1996 PR
related conversation and congratulated Rohit on having got to #4.
I
said it looks like a valuable repository of ideas for people who are coming
into the enterprise NVMe thought space.
In fact I had been alerted to
one of Rohit's earlier blogs in November 2016 by Rebecca Parr who
had been a customer of mine 6 years ago when she was Marcoms Manager at Virident Systems
- which pioneered spikeless performance in fast enterprise PCIe SSDs using its
big SSD
architecture controller design - which was rare at the time but is now the
kind of thinking which has become mainstream in large scale flash arrays.
It's
strange how sometimes it's a series of accidental connections - spaced out
over time - which trigger me to write something here - which in this case is
to say - you might already have read plenty of blogs about NVME SSDs - but
here's another one you might want to read to. And getting to #4 is noteworthy.
Among other things Rohit says..."Beyond performance, the NVMe
protocol also supports IO multipath, which is particularly useful for redundancy
and load balancing purposes... NVMe namespace sharing combined with multipathing
builds the foundation for enterprise-class storage systems." ...read
the article, more
blogs by Rohit Gupta | | |
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| "In 2017, DRAM bit
volume growth was 20%, half the 40% rate of increase registered in 2016. For
2018, each of the 3 major DRAM producers (e.g., Samsung, SK Hynix, and Micron)
have stated that they expect DRAM bit volume growth to once again be about 20%.
However monthly year-over-year DRAM bit volume growth averaged only 13% over
the 9-month period of May 2017 through January 2018." |
| Are
the Major DRAM Suppliers Stunting DRAM Demand? - announcing the new
2018 McClean
Report by IC Insights
(March 6, 2018) | | |
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| "There are a multitude
of trends (way too many to ignore!) that are causing OEM Customers to start
thinking about getting rid of traditional SSDs all together. Now you think Im
crazy, right? As a matter of fact, its already started to happen and its about
to become even more prevalent than you think." |
| Ryan Smith,
(previously Director of Product Marketing - Samsung Semiconductor and now
Product Strategist at Hitachi Vantara) in his article on linkedin -the
SSD Market is about to collapse! Save $100M's by reading this (March 2,
2018) | | |
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| prologing
future application roles for FRAM |
Editor:- March 1, 2018 - Applications for FRAM
are discussed in a new
article on
EETimes. Among other things mentioned in the article - Cypress says its "FRAM
line was designed specifically for the high-speed nonvolatile data logging
needed for autonomous vehicles." ...read the article
- Cypress Sees a Future for FRAM
Editor's comments:- From a
historic perspective
FRAM
(first mentioned in a news story here on StorageSearch back in
November 2002 )
can be seen as a natural successor to the battery backed SRAM which became
popular in industrial equipment designs including programmable controllers and
process control instrumentation in the early 1980s.
But looking
ahead - if there's a need for reliable fast data logging to enable crash
recovery and instant restart and resume state of random state of play
operations in IoT and machine applications which require small scale speed and
reliability rather than masses of streaming data (a role where the capacity of
flash compensates for its poor random write latency) then FRAM is one of
several contenders for designers. | | |
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Micron hints at AI assisted porting of
compute intensive models to FPGA-inside memory array accelerators
Editor:-
March 30, 2018 - A new blog -
Why
Memory Matters in Machine Learning for IoT - by Brad Spiers - Principal
Solutions Architect, Advanced Storage at Micron reveals
significant progress in software tools development which is intended to reduce
the time and complexity of porting machine learning models onto in-situ memory
accelerators implemented by FPGAs embedded into DRAM arrays. The blog makes
specific reference to applications with Micron's PCIe connected
Advanced
Computing Solutions (pdf) - which provide FGAs integrated with either DDR-3
or HMC and a design, simulation and runtime support tools.
Among other
things - Brad Spiers says... "Micron is engaged with machine learning
experts, like FWDNXT, to enable seamless transfer of machine learning models
onto FPGAs. Models are first created in the normal way, using the same software
that data scientists use every day—Caffe, PyTorch or Tensorflow. The
models output by these frameworks are then compiled onto FPGAs by FWDNXT's
Snowflake compiler." ...read
the article
Editor's comments:- creating AI based software
productivity tools which could cut many months off the design time to create
FPGA based in-situ memory based application accelerators is an extreme case of
Memory
Defined Software. Such developments could become as significant for
startups creating blue sky HPC based knowledge enabling tools as was the
availability of microprocessor development systems for the democratization of
digital electronics in the 1970s.
Gb NRAM chips could sample in 2019 - says Nantero
Editor:-
March 29, 2018 - NRAM (a non volatile memory technology which has been in
commercial development since 2001) by Nantero may be
sampling next year with chip densities of 16Gbit - according to an interview
article -
Nantero's
CEO says NRAM production is close on eeNewsAnalog.com - which says the
memory technology supports 5nS write speeds and retention of more than 10
years at 300°C.
Nallatech enters the in-situ SSD market
Editor:-
March 19, 2018 - A new entrant to the in-situ SSD processing market is Nallatech which has
launched
its
250
series of NVMe storage accelerator modules which include application
programmable FPGAs closely coupled with memory. Among the models announced
today:-
- 250S+
- HHHL PCIe SSD accelerator featuring up to 4x M.2 NMVe SSDs and 4GB
SDRAM coupled on-card to a fully programmable Xilinx FPGA.
- 250-U2
- A 2.5" U.2 hot swappable fully-programmable accelerator features a
Xilinx Kintex UltraScale+ FPGA and 8GB DDR4 SDRAM memory.
Nallatech
provides consultancy services assisting customers in the porting, optimization
and benchmarking of applications executed on Nallatech FPGA accelerators.
Nimbus samples 100TB SAS SSDs
Editor:- March 19, 2018
- Nimbus Data Systems
has made another significant advance in the development of multipetabyte
energy-efficient solid state storage racks with the
announcement
today that it's sampling 100TB 3.5
SAS SSDs with
unlimited DWPD.
The
ExaDrive
DC100 has balanced performance 100K
IOPS R/W and
up to 500 MBps throughput and consumes 0.1 watts/TB - which Nimbus says is 85%
lower than competing drives used in similar array applications - such as the
Micron's 7.68TB 5100
SATA SSD.
Nimbus says the use cases are:-
- Data centers and cloud infrastructure (scale, efficiency)
- Scale-out systems (object and file storage)
- Edge computing (IoT, embedded applications)
General availability
is expected to be summer 2018.
ExaDrive technology and
reliability?
I asked Thomas Isakovich,
CEO and founder of Nimbus some questions about the new ExaDrive technology.
Editor - The
50TB models
announced by your flash partners last year used planar 2D flash. Does
the 100TB family use 3D flash? Knowing the answer one way or another will
enable some people to make their own judgements about incremental upsides in the
next year or so's roadmap. And also form a view about specification stability
and reliability.
Tom Isakovich - Yes 3D flash for the ExaDrive DC.
Editor
- The issue of cost per drive is an interesting one too. But the companies you
were working with last year have experience in processes which can produce a
high confidence reliable SSD for high value, mission critical markets (like
military) in which the reliability of every single SSD is critical. So my guess
would be that for integrators who have a serious interest in the ExaDrive DC100
– they will be looking at the cost of drive failures on a system population
basis – and the value of less drives and less heat per TB is more important
than the headline cost of a single failed drive.
Tom Isakovich - I have
an interesting subject for you to consider on the topic of "reliability".
Namely, is an SSD any less reliable than an all-flash array? I contend that it
is not. In fact, an SSD is more reliable.
- Our ExaDrive DC has flash redundancy internally, with the ability to
lose about 8% of flash dies without any downtime, data loss or capacity
reduction. This is analogous to
RAID in a traditional
all-flash array that protects against media failure. So on the notion of media
redundancy, they are equally redundant.
- The ExaDrive DC has a 2.5 million hour MTBF with no moving parts.
That is about 6 times longer than the typical all-flash array (which includes)
many active and moving parts. All-flash arrays have integrated power supplies,
active controllers, fans, and other components prone to failure.
I'm thinking more on this. But empirically, an SSD is more
reliable than a System. The user can achieve desired redundancy in their overall
architecture, taking this into consideration.
See also:-
rackmount SSDs
what's the cost of deciding what is to be done?
Editor:-
March 10, 2018 - "In any computer architecture, it takes a lot more energy
to fetch and schedule an instruction than it does to execute that instruction"
says Rado
Danilak, founder and CEO - Tachyum
- in his new blog -
Moore's
Law Is Dying - So Where Are Its Heirs? - which among other things - shows
how the transactional costs of fetching instructions and data in classical
processors. ...read
the article
Editor's comments:- the needs of the cloud, coupled
with growing understanding between the tradeoffs between
processors,
memory,
controller
dynamics, software
and energy consumption since the widespread deployment of solid state storage
have been the inspiration for rethinking all the classical elements of computer
architecture. Some of that thinking has been rooted in the memory space but
just as significant has been a rethinking of what processors should aim to do.
Tachyum announced external funding for its Cloud Chip
last month. And
as with previous disruptive technologies - part of the warm up process for the
market - is to educate more people about how things work now so they can better
appreciate what the new technologies offer.
WDC's enterprise flash hopes which were pinned on SanDisk are
evaporating - says The Register
Editor:- March 8, 2018 - If you're
interested in seeing market share charts for the biggest enterprise SSD
drive companies then take a look at a new entertaining article -
2
years and $19B later: What happened to WD's SanDisk enterprise flash advantage?
on The Register by Chris Mellor who
says among other things:- "WDC bought SanDisk in October 2015 for $19B. The
deal closed in May 2016. Since then SanDisk CEO Sanjay Mehrotra and a string of
other execs have joined Micron, now run by Mehrotra. It's tempting to see much
of Micron's gain as WDC's loss." ..read
the artticle
Editor's comments:- If the enterprise SSD market
was expected to stay the same in terms of architecture, software and purpose
then today's market shares would mean more.
But as you know I think
the next advance towards supporting big memory apps may make AFAs and enterprise
SSDs seem as quaint as
optical drives.
Enterprise SSDs won't EOL overnight -
storage history
suggests that AFAs and other storage arrays will continue to exist for another
decade or more but as a progressively declining percentage of the
memoryfication systems market. And eventually enterprise storage systems may
just head towards being a legacy emulation in software defined memory
systems and the cloud rather than real actual Storage PHY and on-premises
boxes.
Going back to
WDC and
SanDisk... with
acquisitions come patents too. Maybe they will prove to be more valuable than
product lines.
See also:-
SSD company
acquisitions - 2000 to 2017
mouse site readers not scared by memoryfication of content
Editor:-
March 1, 2018 - Strange as it may seem - article views on StorageSearch.com in February 2018
were 23% higher than the year ago period.
Having written for
so long about SSDs and the impact of flash on the enterprise it would be ever so
easy to just rest awhile longer in those comfortably worn grooves.
To
be truthful it's been a struggle for me to visualize and try to anticipate the
important next step trends of the memoryfication of everything. Unlike storage -
which was relatively simple and well bounded by latency tiers and interfaces
and form factors - the new threads of architectural data system change are
appearing in disparate places - such as memory systems, inside the dark spaces
of processors and slashing across the legacy imaginings of system software.
Unscrambling the next generation possibilities isn't straightforward -
because ever since
about
2016 new developments in rackmount boxes and NVDIMMs and SSD controllers
have not been so isolated in their immediate market impact as they used to
be.
So I'd like to say thanks to my readers for keeping up your
interest and thanks too to the many industry muses who by what they do and say
and talk about - keep me thinking about the next thing. And thanks too to my
customers (advertisers
past and present) without whom my web publishing career would have been 22
years shorter. | |
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| after AFAs
- what's next? |
Throughout the
history of
the data storage market we've always expected the capacity of enterprise user
memory systems to be much smaller than the capacity of all the other attached
storage in the same data processing environment.
 A
classic blog on StorageSearch.com
- cloud
adapted memory systems - asks (among other things) if this will always be
true.
Like many of you - I've been thinking a lot about the
evolution of memory technologies and data architectures in the past year. I
wasn't sure when would be the best time to share my thoughts about this one.
But the timing seems right now. ...read the
article | | |
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| If you're one of those who
suffered from the memory shortages it may seem unfair that despite their
miscalculations and over optimimism the very companies which caused the
shortages of memory and higher prices - the major manufacturers of nand flash
and DRAM - have been among the greatest beneficiaries. |
| re autonomous data destruct
flash SSDs | | |
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| The need for fast data
erase - in which vital parts of a flash SSD are destroyed in seconds - has
always been a requirement in military projects. That's because if a disk falls
into enemy hands the data protection offered by encryption is not safe enough.
Encryption can be defeated in a short period of time by brute force methods and
also by master keys being stolen. |
| RAM disk
emulations in "flash as RAM" solutions | | |
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| Memory
Defined Software - a new market in the making |
There's a new software idea that's been
experimented on in the AI skunkworks in the cloud and as patentable secret
enhancements in next generation embedded processor designs. This new concept and
exciting new market (for the VCs reading this) will be more significant than a
new OS and will mark a break in the way that the enterprise thinks about
software.
You had had plenty of warning about the new chips but
memoryfication doesn't stop with faster storage. The idea didn't have a name
when I started writing about it. But what it should be called is obvious.
Memory
Defined Software doesn't have to work at being backwards compatible
because the legacy storage industry will import and export to it if they want
to play in data's future.
See more about this in my blog -
introducing -
Memory Defined Software. (Sometimes you can change the world with software
which breaks all the rules - if you can find the right platform to run it on.) ...read the
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| classic articles from
SSD history |
9 years ago (March 2010) I published -
this way to the
petabyte SSD - which predicted that flash storage arrays would create a new
market in the enterprise for storage with a lower cost of ownwership than hard
drives - despite the higher cost of flash media. I showed that the pivotal
issues were storage density (petabytes per U) and electrical power. And I argued
that even if hard drives were free - they would still be replaced by flash.
Re a new business model for the SSD data economy I said...
"More
data is better - not worse. Data volumes wll expand due to new intelligence
driven apps. But the data archive will be seen as a profit center - instead of a
cost overhead."
I got some of the detail wrong in that 9 year
lookahead article but the key ideas proved to be right. Talking to founders of
enterprise SSD companies at the time my argument about zero cost (to buy) HDDs
nevertheless giving way to SSDs - was the one which they liked best. ...read the article | | | |
