| Serial Attached SCSI
(SAS) news |
SMART samples 400GB 2.5"
SAS eMLC SSD
Editor:- August 17, 2010 - SMART entered
the crowding SAS SSD
market with the announcement that it is sampling the
XceedIOPS
SAS SSD - a 2.5" 400GB eMLC SSD with 26,000 / 20,000 R/W
IOPS and
250/230 MB/s sustained throughput.
The new XceedIOPS SAS SSD offers
high reliability and data integrity due to extensive error-correction and
detection capabilities, multi-level data-path and code protection, data-fail
recovery, and data-integrity monitoring. Designed to minimize power surges in
SSD arrays the the XceedIOPS SAS SSD supports staggered power-on.
and Super Talent... brings SAS SSD headcount to 14
Editor:-
June 21, 2010 - Super Talent
Technology entered the
2.5"
SAS SSD market by
announcing
imminent shipments of its ShuttleCraft brand - which includes SLC and MLC
models with capacities upto 240GB .
RunCore samples SAS SSDs
Editor:- May 7, 2010 - RunCore is now
sampling (its previously announced)
2.5" and
3.5"
SAS flash SSDs for the
enterprise server market.
The Kylin II product line, available with
MLC, EMLC or SLC
flash, has R/W speeds upto 270MB/s and 260MB/s respectively, R/W
IOPS of
30,000 and 25,000, upto 400GB capacity and 3 years warranty.
and Foremay - makes "lucky 13" SAS SSD oems
Editor:-
April 29, 2010 - Foremay
has started sampling SAS
SSDs in its
EC188
product line.
The new models (available in
2.5" or
3.5" form factors,
and available in commercial and industrial temperature grades) have R/W speeds
of 250MB/s and 200MB/s respectively, random read/write
IOPS up to
30,000/25,000 and upto 400GB capacity.
That brings the number of
SAS SSD companies
listed on StorageSearch.com to 13.
New 8 bay SAS desktop JBOD / RAID
Editor:- April
13, 2010 - Proavio
launched the
EditBox EB8Sx -
an 8 drive desktop
SAS
box (with 750MB/s internal
storage bandwidth) designed for the video editing market.
A single
SAS host port can connect up to 128
disks by adding
additional boxes.
SAS / SATA drive array tester reviewed by Demartek
Editor:-
March 22, 2010 - Quarch
Technology announced that
Demartek
had published a report (pdf) which reviews the usability and benefits of
its SAS/SATA disk array test system.
It's useful for integrators
qualifying components and modules for use in new
RAID systems.
Seagate adds 2TB SAS notch to 18 Years of 7,200 RPM HDDs
Editor:-
February 22, 2010 - Seagate
today
announced
it's shipping 2TB 3.5" 7,200 RPM hard drives with a 6Gbps SAS interface.
The
new
Constellation
ES includes host-selectable power reduction options - upto 35%
for slow or idle periods.
Editor's comments:- coming 6 months
after 2TB SATA
enterprise hard drive shipments from other hard disk oems - (Hitachi
- Ultrastar A7K2000 and
WD
RE4 ) - the distinguishing feature about this is the
SAS interface. But
the "6Gbps" part is vanity rather than substance - because (like all
hard drives) the magnetic media delivers lower throughput and
IOPS than
you can get from many common 3Gbps
2.5"
SATA SSDs.
On
a historical
note Seagate started shipping the world's 1st
7,200
RPM HDDs in 1992.
Toshiba Spins 600GB SAS Drive
Editor:- February 16,
2010 - Toshiba
today
announced
it's sampling a 600GB 2.5"
10K
RPM HDD with 6Gbps
SAS interface.
This
results from the integration of
Toshiba and Fujitsu's
HDD business last year. Some of the new models include drive-based
encryption.
LSI Samples 600k IOPS SAS ROC for SSD Servers
Editor:-
December 16, 2009 - LSI
announced it is
sampling
the LSISAS2208 - a dual-core
6Gb/sSAS
RAID-on-Chip
IC to OEM customers.
It's
intended to support the forthcoming PCIe 3.0 specification, currently under
development and provide performance levels that meet the needs of
next-generation server platforms based on
flash SSD storage
(up to 600,000 IOPS).
WD Ships 2.5" 10K SAS HDDs
Editor:- November
3, 2009 -
Western Digital
announced volume shipments of its 1st
2.5" 10K
RPM SAS hard drive.
The WD S25 provides up to 300 GB of
high-performance storage suitable for both mission-critical enterprise server
and enterprise storage applications, such as high-I/O-driven applications and
configurations, as well as data centers and large data arrays.
"Our entry into the traditional-enterprise market continues the
strategic expansion and diversification of WD's broad market and product
portfolio, and significantly increases our addressable revenue opportunity,"
said John Coyne, president and CEO of WD. "As with our previous market
expansion and diversification efforts, WD will approach the traditional
enterprise space with the same focus on quality, customer service, technology
and value that has earned us strong positions in every market we serve."
Editor's comments:- 15K RPM hard drives are obsolete for new
designs - because if you want acceleration - you get more server bang per buck
using 2.5" SSDs.
But in the 10K area HDDs can still deliver high capacity with tolerable
performance and lower cost than SSDs.
In order to optimize overall economy,
reliability and
performance - the well architected enterprise storage systems of the near term
future will lean towards using more 10K RPM (and slower)
hard drives - for bulk
content - and towards using various levels of SSDs for performance. In the long
term it will all be solid state - but that's still 10 years away.
Unigen Signals 2.5" SAS SSD Intent
Editor:-
November 2, 2009 -
Unigen announced
it will manufacture a new range of
flash SSDs using
SSD processors from SandForce.
The 2.5"
SSDs will be available with
SATA or
SAS interfaces.
Fusion-io Ousts SAS HDD RAID at MySpace
Editor:-
October 13, 2009 - Fusion-io
published a
case
study showing how their ioDrive
SSDs helped MySpace reduce
servers, claim back 50% rack space while increasing application performance and
massively decreasing electrical power.
The ioDrives performed much
better than the legacy SAS
disk arrays, but more importantly for MySpace, they did it with much less
hardware. A single ioDrive allowed MySpace to replace a 2U HP DL380 server with
1U HP DL160 server.
In the initial phase of this deployment MySpace
replaced 150 of their standard load servers, recovering 150U of rack space.
Additionally, the ioDrives' phenomenal performance reduced its need for heavy
load servers, allowing it to permanently end-of-life 50 of 80 heavy load
servers. This allowed it to recover another 65U of rack space.
Reliability also
increased and the Fusion-io solution is
greener.
Estimates suggest that the power savings alone could easily pay for the
ioDrives over their lifetime.
MySpace says it plans to replace
another 1,770 2U servers with Fusion-io enabled servers as they reach their
end-of-life. ...read the
article (pdf)
Editor's comments:- If you ever wondered why
there are so few companies making
SAS SSDs - this is one
of the reasons. And it's also why search volume for
PCIe SSDs is now
higher than that for 2.5"
SSDs. See also:- Market
Trends in the Rackmount SSD Market
Pliant Samples Fast 2.5" 3.5" SAS SSDs
Editor:-
September 14, 2009 - Pliant
Technology started sampling its
Lightning
family of 2.5"
(150GB) and 3.5"
(300GB) skinny
flash SAS SSDs.
The SLC drives deliver R/W rates upto 525/340MB/s and 160,000 IOPS
(for a 90% R, 10% W mix).
Editor's comments:- the
realistically addressable market
for native SAS SSDs in disk form factors looks a lot smaller today than 3
years ago when Pliant was founded. That's because SAS SSD opportunities have
been shunted aside by PCIe
SSDs and squeezed from below by fast
SATA SSDs.
The
result has been that SSD vendors have been reluctant to enter this part of
market. But the good news for the handful of companies actually shipping such
products is they don't have to worry about dozens of competitors going for every
design slot. That means higher margins for the forseeable future. Pricing for
a single EFD is expected to fall between $15/GB and $30/GB.
ATTO Demos 6,400MB/s HBA at IBC
Editor:- September
10, 2009 - ATTO
Technology is
demonstrating
its 6Gb/s SAS HBAs
and 8Gb/s Fibre Channel HBAs this week at IBC
in Amsterdam .
Demos include a quad-channel card that delivers the
fastest available Fibre
Channel data transfer rate of 6,400MB/s. Storage Events,
Record Breaking
Storage
STEC Samples 6Gb/s SAS SSDs
Editor:- August 11, 2009
- STEC today
said
it will ship 6Gb/s SAS
flash SSDs in both 2.5"
and 3.5" form
factors in Q4.
STEC's new ZeusIOPS SSDs will deliver 80,000 IOPS
random read, 40,000 IOPS random write with transfer speeds of 550MB/s read and
300MB/s write.
STEC also said it's
sampling
a faster version of its 3.5"
FC compatible SSDs.
STEC
also announced a new policy of offering
MLC flash
in so called "enterprise class SSDs".
"While we
believe our core customers will continue to rely on and demand our industry
leading SLC based SSDs, it is apparent that several of our price sensitive OEM
customers are now looking for SSD alternatives which only a true MLC based SSD
can deliver" said Manouch Moshayedi, Chairman and CEO of STEC.
Editor's
comments:- the attraction of stuffing flash SSD arrays with
MLC instead of SLC
is simply - price.
Fusion-io's CTO -
David Flynn recently told me there is as much as a 4x difference in
price between MLC and SLC NAND flash.
Proponents of MLC enterprise
flash SSDs say their SSD
controllers do more than simply attenuate write cycles to a level where
you don't need to worry about
endurance.
SandForce,
for example, says its SSD processor understands chip geometries and minimizes
read disturb errors.
In my view there are risks in using MLC flash in
some types of enterprise apps - which go far beyond than the endurance problem -
as I described in Are
MLC SSDs Ever Safe in Enterprise Apps? Nevertheless there are some
enterprise applications where low levels of data corruption / data loss are
tolerable - for example streaming video servers. Cautious users could get the
best of both worlds by partitioning their SSD accelerator zones between SLC
and MLC according to the risk / reward preferences for different data sets
within their applications.
Adaptec Ships Flash Cache Backup for SAS RAID Controllers
Editor:-
June 24, 2009 - Adaptec
today announced the availability of
flash
backup options for its SATA/SAS
RAID controllers.
Adaptec's
Zero-Maintenance Cache Protection protects data stored in controller cache for
up to 10 years with no installation, monitoring, maintenance, disposal or
replacement costs unlike lithium batteries.
Editor's comments:-
the industry's 1st flash cache backup module for RAID controllers was
announced in February
2009 by Viking
Modular Solutions.
What are the Prospects for SAS SSDs?
Editor:- May
12, 2009 - how popular is SAS compared to other interfaces when it comes to
reader searches for SSDs?
Form factor remains the #1 search criterion
for SSDs, ever since we started tracking SSD user preferences
5 years ago. That's
hardly surprising - because if the product doesn't conveniently fit into the
space planned for it - then a major rethink is required. And interface type is
the next main consideration - for similar reasons.
Only 6% of
SSD oems market
SAS compatible SSDs.
That's much less than I would have expected a few years ago.
Part of
the reason may be that the enterprise market is still
confused and
unsure about whether the best way to tackle locally connected SSDs is as small
form factor disks (2.5"
and
3.5"), or
PCIe compatible cards
or rackmounts.
Add in the recession factor - and you can see why most SSD product
marketers have been playing it safe - and not rushing to offer SAS SSD
product lines.
I looked at storage search volumes in April 2009 -
which revealed the following.
In searches for SSDs by interface type -
SAS was already 10% higher than searches for
FC compatible SSDs.
SATA SSDs
accounted for just over 2x as many searches as SAS SSDs. That understates the
volume and popularity of SATA SSDs - but the discrepancy is explained by the
fact that once a reader has found the directory for small form factor SSDs -
most of the products they see already match their needs and have a SATA or PATA
interface. It's only at the high end of the performance range for SFF SSDs that
readers realize it's more productive to search by interface.
The real
excitement in the enterprise SSD market though is being caused by the PCIe
mavericks who collectively have made searches for PCIe SSDs 7x more
popular than SAS SSDs. Users and system designers seem to be buying into the
concept of ripping up their old ideas of what package a storage module should
come in - for the extra benefit of getting faster performance.
Overall
this suggests that SSDs will not follow the same interface adoption patterns
set by hard drives.
Users will choose whatever SSD technology gives them the best tactical options
for each type of application - rather than follow a single pattern. | |
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Serial Attached
SCSI - Delivering Flexibility to the Data Center - article by LSI Logic and
Maxtor
If you think you already know SAS because you
know SATA and traditional SCSI then think again.
Sometimes disruptive
technologies wear an unassuming disguise. In fiction, Clark Kent, Frodo Baggins
and Buffy Summers at first seem harmless, but we see them change into Superman,
the Ring Bearer and the Slayer.
SAS too comes cloaked in plain garb -
with a physical layer which looks a lot like SATA. But like the Incredible Hulk
there are muscles rippling under that shirt - and you would be wrong to dismiss
SAS so lightly. There's a lot more inside this interface than it says on the box
as this informative article reveals. ...read the article | |
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Serial Attached SCSI
SAS
technology enables SCSI interface solutions beyond Ultra320 to the
next-generation Direct Attach Storage enterprise server, storage systems, and
high-performance workstation markets while retaining device-level backward
compatibility. The SAS standard defines a device-level enterprise storage
interface incorporating SCSI command sets, serial point-to-point
interconnections, dual porting, increased addressability and the ability to
scale to small form factors. Because the SAS physical layer is compatible with
Serial ATA (SATA), users will have the choice of populating their systems with
SAS or SATA hard disk drives, or a combination of both.
...from a joint
press release by LSI Logic
and Tabernus | |
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| Serial
Attached SCSI Timeline |
STORAGEsearch.com was the
first publication to provide a dedicated
Serial Attached SCSI
page in November 2001, the same month in which the new standard was first
publicly announced.
The first functioning silicon for this was
demonstrated in January 2004 by LSI Logic. Host Bus Adapters and chipsets
supporting this new standard start shipping to storage system designers in
April/May 2004 from various companies.
Here's a timeline of how SAS
moved from vaporware to reality.
- November 2004 - Serial Attached SCSI moved into the
top 20 most popular subjects viewed by STORAGEsearch readers for the first time.
- February 2005 - IBM ships SAS in x366 servers
- May 2005 - Hitachi Ships 15K RPM SAS Hard Drives
- June 2005 - HP announces that SAS will be used in
ProLiant Dual-Core AMD Opteron-based servers
- September 2005 - LSI Logic discloses that Dell and
Sun will soon ship SAS based servers
- October 2005 - Seagate & Adaptec Launch 1/2
Price SAS Starter Kit
- December 2005 - Maxtor & LSI Logic Offer Rebate
to Early SAS Adopters
- January 2006 - StorCase ships first removable SAS
drive enclosures.
- July 2006 - SAS enters the top 10 storage searches
by
STORAGEsearch.com readers for the
first time.
- April 2007 - Hitachi
announces 15k RPM, 300GB SAS HDDs.
- April 2008 - Seagate
Technology starts volume shipments of 7,200 RPM SAS compatible terabyte
HDDs.
Why is the new standard necessary?
Without
faster storage - typically upto 50% of the potential performance in
modern server processors is wasted.
Serial Attached SCSI (SAS)
provides a software compatible upgrade for directly attached SCSI storage which
provides much higher performance than Ultra320 SCSI. So this is the least pain
next step for SCSI users. Although, as with all new technology there is a
learning curve.
The popularity of Internet SCSI (iSCSI) protocol
products in the second half of 2003 proved that the base of server owners who
are familiar with SCSI - will go a long way to adopt new connectivity options
which leverage concepts they trust and are familiar with. Asimilar evolution
took place with Ethernet, which started as a 3Mbps standard and still looks
viable at 10Gbps. Computer users like stuff that is newer faster and cheaper,
but we all know that "newer" also means "buggier" if we are
the first users. Anything that reduces the amount of new code and risk along
the way gets our vote.
SAS will meet the threat (albeit late in
marketing terms) from Serial
ATA (SATA),
FireWire and
USB 2. In fact SAS uses the
same electrical interface and cables as SATA. That's good news if you're worried
about stocking even more types of cables. It also simplifies the rollout of new
test equipment - because
products designed for SATA can be adapted to SAS more simply (in theory by
firmware upgrades.)
20+ years ago, when SCSI started, it suited the
clock speeds and cable transmission driving capabilities of the TTL compatible
logic which was the standard at the time. SCSI was also easy to connect using
standard low technology ribbon cable. Since then, most of the enhancements in
the SCSI standard have focused on getting it to work faster, using higher clock
speeds, a wider data bus, lower logic levels and differential signals.
Serial
Attached SCSI is the first real attempt in SCSI history to lower cost and
simplify the physical connection. Past performance upgrades came from increasing
the number of cable cores. But the new high speed serial SCSI cables should be
cheaper than the lower performance parallel SCSI ones which they replace. And
you won't have to worry any more about those termination nightmares. It's
simpler in a serial system to automatically monitor signal quality and
dyamically adjust to the cable and connector transmission characteristics.
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