SAS SSDs -
vendors, news, market
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| Genesis of
the Serial Attached SCSI SSD Market |
SAS SSDs have been a
long time acoming - and for many years there were only 1 or 2 vendors in the
market.
One flash
SSD oem (Adtron) had
even said publicly in
2007 they
couldn't
see the need for SAS SSDs at all - because the leap in performance going from
hard drives to
SATA flash SSDs was
already so great - that the marginal difference of SAS wouldn't be worthwhile.
In one way that thinking was right. Users would expect a
lot of performance in
SAS flash SSDs - and the best ways to do that were being tested in the market
for SATA and
fibre-channel SSDs.
But it was wrong to think that users wouldn't recognize and be willing to pay
for the extra performance available from SAS. When your server already speaks
fluently optimized phrases in SCSI-speak - then you will get significantly
more performance from native speaking SAS SSDs - more than predicted from the
raw difference that SAS can read and write at the same time.
SAS SSD milestones from
storage history
November
2001 - Serial Attached SCSI is proposed as a new interface.
StorageSearch.com became the 1st
publisher to set up a dedicated directory for
SAS storage.
January
2005 - the SSD
buyers survey showed SAS SSDs as the 8th most desirable SSD interface to
meet buyers' future needs. The #1 on this list (with 5x as many responders
saying they would use it) was
SATA SSDs - although
at the time of the survey - neither type of product actually existed.
April
2005 -
Solid Access
Technologies made the first SSD with a SAS interface. It was a rackmount
RAM SSD.
August
2007 - STEC
announced it was designing a 3.5" SAS SSD.
December 2008
- Hitachi and
Intel announced they were
jointly designing a new range of high IOPS flash SSDs with
SAS interfaces -
expected to ship in Q1 2010.
January 2009 - As the number of
oems talking about SAS SSDs headed towards double digits - StorageSearch.com
launched a dedicated directory page for
SAS SSDs. |
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| SAS SSD news - below /
all SSD news |
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Viking Enters 2.5"
6Gbps SAS SSD Market
Editor:- January 21, 2010 - Viking Modular Solutions
today announced
it is sampling a range of SAS
and SATA compatible
SSDs using
controllers from SandForce.
Form
factors will include:- 1.8",
2.5" and
innovative "non-HDD-like"
solutions for space constrained and/or rugged applications.
OCZ Promises "SandForce inside" SAS SSDs
Editor:-
November 10, 2009 - OCZ
today
announced
it will launch a new SAS
SSD family based on SSD
SoCs from SandForce
which will probably be previewed at CES
in January 2010.
Editor's comments:- for more examples of who
else has already announced SandForce based SSDs (and in some cases is already
shipping them) see the article -
3 Easy Ways to Enter
the SSD Market.
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.
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).
"The exceptional performance and
reliability features of Lightning Enterprise Flash Drives allow IT managers to
address the most significant challenges they're facing today, namely, keeping up
with continually increasing storage demands with fixed budgets, limited data
center floor space and the ever growing cost of power," said Amyl Ahola,
CEO of Pliant Technology.
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.
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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Megabyte had already mastered
serial SCSI
for RPM storage - so SAS SSDs were a breeze. | |
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| There
are
hundreds
of articles about SSDs on StorageSearch.com |
Here, below, are some
examples.
- RAM Cache
Ratios in flash SSDs - it's important to know the underlying RAM cache
architecture - even if you're happy with the R/W and IOPS performance.
- 2010 - 1st Fizz
in the SSD Bubble? - even the dogs in the street know this is going to be a
multibillion dollar market. Greed will play as big a part as technology in
shaping the
SSD year ahead.
- the pros and cons of
using SSD ASAPs - auto tuning SSD appliances are a new category of SSD
which entered the market in the 2nd half of 2009 to accelerate servers without
needing human tune-ups. How can you tell if they are right for you? And how
well do they work?
- the Problem
with Write IOPS - in flash SSDs - long established as a useful performance
modeling metric - this article explains why some specs are exaggerated when
applied to flash SSDs - or predict the wrong results for many common
applications.
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