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* Intel's X25-M SSD
@ 2008-09-08 23:12 Greg Smith <gsmith@gregsmith.com>
2008-09-08 23:59 ` Re: Intel's X25-M SSD Merlin Moncure <mmoncure@gmail.com>
2008-09-09 00:19 ` Re: Intel's X25-M SSD Scott Carey <scott@richrelevance.com>
2008-09-23 04:48 ` Re: Intel's X25-M SSD Simon Riggs <simon@2ndQuadrant.com>
0 siblings, 3 replies; 9+ messages in thread
From: Greg Smith @ 2008-09-08 23:12 UTC (permalink / raw)
To: pgsql-performance
If like me you've been reading all the flash SSD drive reviews that come
out, you might have also noticed that the performance on write-heavy
workloads hasn't been too far ahead of traditional drives. It's typically
been hit or miss as to whether the SDD would really be all that much
faster on a real OLTP-ish database workload, compared to a good 10k or 15k
drive (WD's Velociraptor is the usual comparison drive).
That's over as of today: http://techreport.com/articles.x/15433/9
You can see what I was talking about above in their Database graph:
under heavy load, the Velociraptor pulls ahead of even a good performing
flash product (Samsung's FlashSSD), and the latency curve on the next page
shows something similar. But the Intel drive is obviously a whole
different class of SSD implementation altogether. It's not clear yet if
that's because of their NCQ support, or maybe the firmware just buffers
writes better (they should have tested with NCQ disabled to nail that
down).
With entry-level 64GB Flash drives now available for just under $200 (
http://www.newegg.com/Product/Product.aspx?Item=N82E16820227344 , price is
so low because they're closing that model out for a better V2 product)
this space is really getting interesting.
--
* Greg Smith gsmith@gregsmith.com http://www.gregsmith.com Baltimore, MD
^ permalink raw reply [nested|flat] 9+ messages in thread
* Re: Intel's X25-M SSD
2008-09-08 23:12 Intel's X25-M SSD Greg Smith <gsmith@gregsmith.com>
@ 2008-09-08 23:59 ` Merlin Moncure <mmoncure@gmail.com>
2008-09-09 15:03 ` Re: Intel's X25-M SSD Chris Browne <cbbrowne@acm.org>
2008-09-20 03:23 ` Re: Intel's X25-M SSD Greg Smith <gsmith@gregsmith.com>
2 siblings, 2 replies; 9+ messages in thread
From: Merlin Moncure @ 2008-09-08 23:59 UTC (permalink / raw)
To: Greg Smith <gsmith@gregsmith.com>; +Cc: pgsql-performance
On Mon, Sep 8, 2008 at 7:12 PM, Greg Smith <gsmith@gregsmith.com> wrote:
> If like me you've been reading all the flash SSD drive reviews that come
> out, you might have also noticed that the performance on write-heavy
> workloads hasn't been too far ahead of traditional drives. It's typically
> been hit or miss as to whether the SDD would really be all that much faster
> on a real OLTP-ish database workload, compared to a good 10k or 15k drive
> (WD's Velociraptor is the usual comparison drive).
>
> That's over as of today: http://techreport.com/articles.x/15433/9
>
> You can see what I was talking about above in their Database graph: under
> heavy load, the Velociraptor pulls ahead of even a good performing flash
> product (Samsung's FlashSSD), and the latency curve on the next page shows
> something similar. But the Intel drive is obviously a whole different class
> of SSD implementation altogether. It's not clear yet if that's because of
> their NCQ support, or maybe the firmware just buffers writes better (they
> should have tested with NCQ disabled to nail that down).
What's interesting about the X25 is that they managed to pull the
numbers they got out of a MLC flash product. They managed this with a
DRAM buffer and the custom controller. Their drive is top dollar for
a MLC product but also provides top notch performance (again, for a
MLC product).
The Intel SLC flash products, also due to be out in '08 are what are
most likely of interest to database folks. I suspect prices will
quickly drop and you will start hearing about flash in database
environents increasingly over the next year or two. We are only a
round or two of price cuts before flash starts looking competitive vs
15k sas products in light of all the advantages. This will spur
price cuts on high margin server product drives, which will also cut
r&d budgets. I'll stick to the predictions I made several months
ago...flash will quickly replace drives in most environments outside
of mass storage, with significant market share by 2010. I think the
SSD manufacturers made a tactical error chasing the notebook market
when they should have been chasing the server market...but in the end
the result will be the same.
This should mean really interesting things to the database world.
merlin
^ permalink raw reply [nested|flat] 9+ messages in thread
* Re: Intel's X25-M SSD
2008-09-08 23:12 Intel's X25-M SSD Greg Smith <gsmith@gregsmith.com>
2008-09-08 23:59 ` Re: Intel's X25-M SSD Merlin Moncure <mmoncure@gmail.com>
@ 2008-09-09 15:03 ` Chris Browne <cbbrowne@acm.org>
1 sibling, 0 replies; 9+ messages in thread
From: Chris Browne @ 2008-09-09 15:03 UTC (permalink / raw)
To: pgsql-performance
mmoncure@gmail.com ("Merlin Moncure") writes:
> I think the SSD manufacturers made a tactical error chasing the
> notebook market when they should have been chasing the server
> market...
That's a very good point; I agree totally!
--
output = reverse("moc.enworbbc" "@" "enworbbc")
http://www3.sympatico.ca/cbbrowne/nonrdbms.html
"We are all somehow dreadfully cracked about the head, and sadly need
mending." --/Moby-Dick/, Ch 17
^ permalink raw reply [nested|flat] 9+ messages in thread
* Re: Intel's X25-M SSD
2008-09-08 23:12 Intel's X25-M SSD Greg Smith <gsmith@gregsmith.com>
2008-09-08 23:59 ` Re: Intel's X25-M SSD Merlin Moncure <mmoncure@gmail.com>
@ 2008-09-20 03:23 ` Greg Smith <gsmith@gregsmith.com>
2008-09-24 03:24 ` Re: Intel's X25-M SSD Bruce Momjian <bruce@momjian.us>
1 sibling, 1 reply; 9+ messages in thread
From: Greg Smith @ 2008-09-20 03:23 UTC (permalink / raw)
To: Merlin Moncure <mmoncure@gmail.com>; +Cc: pgsql-performance
On Mon, 8 Sep 2008, Merlin Moncure wrote:
> What's interesting about the X25 is that they managed to pull the
> numbers they got out of a MLC flash product. They managed this with a
> DRAM buffer and the custom controller.
I finally found a good analysis of what's wrong with most of the cheap MLC
drives:
http://www.anandtech.com/cpuchipsets/intel/showdoc.aspx?i=3403&p=7
240ms random write latency...wow, no wonder I keep hearing so many reports
of cheap SSD just performing miserably. JMicron is one of those companies
I really avoid, never seen a design from them that wasn't cheap junk.
Shame their awful part is in so many of the MLC flash products.
--
* Greg Smith gsmith@gregsmith.com http://www.gregsmith.com Baltimore, MD
^ permalink raw reply [nested|flat] 9+ messages in thread
* Re: Intel's X25-M SSD
2008-09-08 23:12 Intel's X25-M SSD Greg Smith <gsmith@gregsmith.com>
2008-09-08 23:59 ` Re: Intel's X25-M SSD Merlin Moncure <mmoncure@gmail.com>
2008-09-20 03:23 ` Re: Intel's X25-M SSD Greg Smith <gsmith@gregsmith.com>
@ 2008-09-24 03:24 ` Bruce Momjian <bruce@momjian.us>
2008-09-24 04:25 ` Re: Intel's X25-M SSD Scott Carey <scott@richrelevance.com>
0 siblings, 1 reply; 9+ messages in thread
From: Bruce Momjian @ 2008-09-24 03:24 UTC (permalink / raw)
To: Greg Smith <gsmith@gregsmith.com>; +Cc: Merlin Moncure <mmoncure@gmail.com>; pgsql-performance
Greg Smith wrote:
> On Mon, 8 Sep 2008, Merlin Moncure wrote:
>
> > What's interesting about the X25 is that they managed to pull the
> > numbers they got out of a MLC flash product. They managed this with a
> > DRAM buffer and the custom controller.
>
> I finally found a good analysis of what's wrong with most of the cheap MLC
> drives:
>
> http://www.anandtech.com/cpuchipsets/intel/showdoc.aspx?i=3403&p=7
>
> 240ms random write latency...wow, no wonder I keep hearing so many reports
> of cheap SSD just performing miserably. JMicron is one of those companies
> I really avoid, never seen a design from them that wasn't cheap junk.
> Shame their awful part is in so many of the MLC flash products.
I am surprised it too so long to identify the problem.
--
Bruce Momjian <bruce@momjian.us> http://momjian.us
EnterpriseDB http://enterprisedb.com
+ If your life is a hard drive, Christ can be your backup. +
^ permalink raw reply [nested|flat] 9+ messages in thread
* Re: Intel's X25-M SSD
2008-09-08 23:12 Intel's X25-M SSD Greg Smith <gsmith@gregsmith.com>
2008-09-08 23:59 ` Re: Intel's X25-M SSD Merlin Moncure <mmoncure@gmail.com>
2008-09-20 03:23 ` Re: Intel's X25-M SSD Greg Smith <gsmith@gregsmith.com>
2008-09-24 03:24 ` Re: Intel's X25-M SSD Bruce Momjian <bruce@momjian.us>
@ 2008-09-24 04:25 ` Scott Carey <scott@richrelevance.com>
2008-09-24 11:11 ` Re: Intel's X25-M SSD Steve Clark <sclark@netwolves.com>
0 siblings, 1 reply; 9+ messages in thread
From: Scott Carey @ 2008-09-24 04:25 UTC (permalink / raw)
To: Bruce Momjian <bruce@momjian.us>; +Cc: Greg Smith <gsmith@gregsmith.com>; Merlin Moncure <mmoncure@gmail.com>; pgsql-performance
A fantastic review on this issue appeared in July:
http://www.alternativerecursion.info/?p=106
And then the same tests on a RiData SSD show that they are the same drive
with the same characteristics:
http://www.alternativerecursion.info/?p=276
Most blamed it on MLC being "slow" to write compared to SLC. Technically,
it is slower, but not by a whole lot -- we're talking a low level difference
of tens of microseconds. A 250ms latency indicates an issue with the
controller chip. SLC and MLC share similar overall performance
characteristics at the millisecond level. The truth is that MLC designs
were low cost designs without a lot of investment in the controller chip.
The SLC designs were higher cost designs that focused early on on making
smarter and more expensive controllers. SLC will always have an advantage,
but it isn't going to be by several orders of magnitude like it was before
Intel's drive appeared. Its going to be by factors of ~2 to 4 on random
writes in the long run. However, for all flash based SSD devices, there are
design tradeoffs to make. Maximizing writes sacrifices reads, maximizing
random access performance reduces streaming performance and capacity. We'll
have a variety of devices with varying characteristics optimal for different
tasks.
On Tue, Sep 23, 2008 at 8:24 PM, Bruce Momjian <bruce@momjian.us> wrote:
> Greg Smith wrote:
> > On Mon, 8 Sep 2008, Merlin Moncure wrote:
> >
> > > What's interesting about the X25 is that they managed to pull the
> > > numbers they got out of a MLC flash product. They managed this with a
> > > DRAM buffer and the custom controller.
> >
> > I finally found a good analysis of what's wrong with most of the cheap
> MLC
> > drives:
> >
> > http://www.anandtech.com/cpuchipsets/intel/showdoc.aspx?i=3403&p=7
> >
> > 240ms random write latency...wow, no wonder I keep hearing so many
> reports
> > of cheap SSD just performing miserably. JMicron is one of those
> companies
> > I really avoid, never seen a design from them that wasn't cheap junk.
> > Shame their awful part is in so many of the MLC flash products.
>
> I am surprised it too so long to identify the problem.
>
> --
> Bruce Momjian <bruce@momjian.us> http://momjian.us
> EnterpriseDB http://enterprisedb.com
>
> + If your life is a hard drive, Christ can be your backup. +
>
> --
> Sent via pgsql-performance mailing list (pgsql-performance@postgresql.org)
> To make changes to your subscription:
> http://www.postgresql.org/mailpref/pgsql-performance
>
^ permalink raw reply [nested|flat] 9+ messages in thread
* Re: Intel's X25-M SSD
2008-09-08 23:12 Intel's X25-M SSD Greg Smith <gsmith@gregsmith.com>
2008-09-08 23:59 ` Re: Intel's X25-M SSD Merlin Moncure <mmoncure@gmail.com>
2008-09-20 03:23 ` Re: Intel's X25-M SSD Greg Smith <gsmith@gregsmith.com>
2008-09-24 03:24 ` Re: Intel's X25-M SSD Bruce Momjian <bruce@momjian.us>
2008-09-24 04:25 ` Re: Intel's X25-M SSD Scott Carey <scott@richrelevance.com>
@ 2008-09-24 11:11 ` Steve Clark <sclark@netwolves.com>
0 siblings, 0 replies; 9+ messages in thread
From: Steve Clark @ 2008-09-24 11:11 UTC (permalink / raw)
To: Scott Carey <scott@richrelevance.com>; +Cc: Bruce Momjian <bruce@momjian.us>; Greg Smith <gsmith@gregsmith.com>; Merlin Moncure <mmoncure@gmail.com>; pgsql-performance
Scott Carey wrote:
> A fantastic review on this issue appeared in July:
> http://www.alternativerecursion.info/?p=106
> And then the same tests on a RiData SSD show that they are the same
> drive with the same characteristics:
> http://www.alternativerecursion.info/?p=276
>
> Most blamed it on MLC being "slow" to write compared to SLC.
> Technically, it is slower, but not by a whole lot -- we're talking a low
> level difference of tens of microseconds. A 250ms latency indicates an
> issue with the controller chip. SLC and MLC share similar overall
> performance characteristics at the millisecond level. The truth is that
> MLC designs were low cost designs without a lot of investment in the
> controller chip. The SLC designs were higher cost designs that focused
> early on on making smarter and more expensive controllers. SLC will
> always have an advantage, but it isn't going to be by several orders of
> magnitude like it was before Intel's drive appeared. Its going to be by
> factors of ~2 to 4 on random writes in the long run. However, for all
> flash based SSD devices, there are design tradeoffs to make. Maximizing
> writes sacrifices reads, maximizing random access performance reduces
> streaming performance and capacity. We'll have a variety of devices
> with varying characteristics optimal for different tasks.
>
> On Tue, Sep 23, 2008 at 8:24 PM, Bruce Momjian <bruce@momjian.us
> <mailto:bruce@momjian.us>> wrote:
>
> Greg Smith wrote:
> > On Mon, 8 Sep 2008, Merlin Moncure wrote:
> >
> > > What's interesting about the X25 is that they managed to pull the
> > > numbers they got out of a MLC flash product. They managed this
> with a
> > > DRAM buffer and the custom controller.
> >
> > I finally found a good analysis of what's wrong with most of the
> cheap MLC
> > drives:
> >
> >
> http://www.anandtech.com/cpuchipsets/intel/showdoc.aspx?i=3403&p=7
> <http://www.anandtech.com/cpuchipsets/intel/showdoc.aspx?i=3403&p=7;
> >
> > 240ms random write latency...wow, no wonder I keep hearing so
> many reports
> > of cheap SSD just performing miserably. JMicron is one of those
> companies
> > I really avoid, never seen a design from them that wasn't cheap junk.
> > Shame their awful part is in so many of the MLC flash products.
>
> I am surprised it too so long to identify the problem.
>
> --
> Bruce Momjian <bruce@momjian.us <mailto:bruce@momjian.us>>
> http://momjian.us
> EnterpriseDB http://enterprisedb.com
>
> + If your life is a hard drive, Christ can be your backup. +
>
> --
> Sent via pgsql-performance mailing list
> (pgsql-performance@postgresql.org
> <mailto:pgsql-performance@postgresql.org>)
> To make changes to your subscription:
> http://www.postgresql.org/mailpref/pgsql-performance
>
>
Anybody know of any tests on systems that have specific filesystems for
flash devices?
^ permalink raw reply [nested|flat] 9+ messages in thread
* Re: Intel's X25-M SSD
2008-09-08 23:12 Intel's X25-M SSD Greg Smith <gsmith@gregsmith.com>
@ 2008-09-09 00:19 ` Scott Carey <scott@richrelevance.com>
2 siblings, 0 replies; 9+ messages in thread
From: Scott Carey @ 2008-09-09 00:19 UTC (permalink / raw)
To: Greg Smith <gsmith@gregsmith.com>; +Cc: pgsql-performance
I have been paying close attention to the recent SSD performance/price
changes with a keen eye to server performance on various workloads and
applications.
The real barrier is in the controller design, and IP surrounding that. All
flash products with any amount of wear-leveling map logical addresses to
physical flash addresses dynamically. An intelligent controller, with
enough processing power and RAM (Intel's drive has 16MB of DDR SDRAM) and an
intelligent design can translate ALL random writes into a sequential
stream. With enough overprovisioning, the erasing and cleaning that goes on
in the background will have very minimal impact. One thing many people will
claim about a SSD is that the erasing and block management will get slower
as the drive becomes more full. This is incorrect -- from the point of view
of any block device it is always 100% full, it is not privy to the file
system notion of 'free space'. Addresses are simply overwritten, which
makes blocks that previously mapped to those addresses available for
writing. By definition, every write is an overwrite.
This paper, is very enlightening:
http://research.microsoft.com/users/vijayanp/papers/ssd-usenix08.pdf
Given Intel's particular strenghts and engineering resources, its not a
surprise that they are among the first to make a design like this (FusioIO
seems to have solved the random write performance issue as well ?). But as
the review you provided links to demonstrates, it is this IP that will
provide the performance gains necessary for flash performance to be hands
down better than all drives, for all workloads, all the time. It is the same
IP that will provide the most longevity and reliability.
Also of note for others reading this thread, the review was for Intel's
"mainstream" device, not the "enterprise" one. The enterprise one claims
3300 random 4k writes/sec and over twice the write throughput. I'm sure it
will also cost twice as much for less capacity.
Of particular interest in the short term may be using cheaper, read-biased
flash drives for ZFS L2ARC caches for a database -- it may be like running
with a couple hundred extra gigs of RAM, but you can still use slow, big
drives for mass storage. The price is prohibitive for putting your whole db
on flash if it is not a small one, but this is not true if you're just
talking about cache devices or xlogs or temp space.
http://blogs.sun.com/brendan/entry/test
On Mon, Sep 8, 2008 at 4:12 PM, Greg Smith <gsmith@gregsmith.com> wrote:
> If like me you've been reading all the flash SSD drive reviews that come
> out, you might have also noticed that the performance on write-heavy
> workloads hasn't been too far ahead of traditional drives. It's typically
> been hit or miss as to whether the SDD would really be all that much faster
> on a real OLTP-ish database workload, compared to a good 10k or 15k drive
> (WD's Velociraptor is the usual comparison drive).
>
> That's over as of today: http://techreport.com/articles.x/15433/9
>
> You can see what I was talking about above in their Database graph: under
> heavy load, the Velociraptor pulls ahead of even a good performing flash
> product (Samsung's FlashSSD), and the latency curve on the next page shows
> something similar. But the Intel drive is obviously a whole different class
> of SSD implementation altogether. It's not clear yet if that's because of
> their NCQ support, or maybe the firmware just buffers writes better (they
> should have tested with NCQ disabled to nail that down).
>
> With entry-level 64GB Flash drives now available for just under $200 (
> http://www.newegg.com/Product/Product.aspx?Item=N82E16820227344 , price is
> so low because they're closing that model out for a better V2 product) this
> space is really getting interesting.
>
> --
> * Greg Smith gsmith@gregsmith.com http://www.gregsmith.com Baltimore, MD
>
> --
> Sent via pgsql-performance mailing list (pgsql-performance@postgresql.org)
> To make changes to your subscription:
> http://www.postgresql.org/mailpref/pgsql-performance
>
^ permalink raw reply [nested|flat] 9+ messages in thread
* Re: Intel's X25-M SSD
2008-09-08 23:12 Intel's X25-M SSD Greg Smith <gsmith@gregsmith.com>
@ 2008-09-23 04:48 ` Simon Riggs <simon@2ndQuadrant.com>
2 siblings, 0 replies; 9+ messages in thread
From: Simon Riggs @ 2008-09-23 04:48 UTC (permalink / raw)
To: Greg Smith <gsmith@gregsmith.com>; +Cc: pgsql-performance
On Mon, 2008-09-08 at 19:12 -0400, Greg Smith wrote:
> If like me you've been reading all the flash SSD drive reviews...
Great post, thanks for the information.
--
Simon Riggs www.2ndQuadrant.com
PostgreSQL Training, Services and Support
^ permalink raw reply [nested|flat] 9+ messages in thread
end of thread, other threads:[~2008-09-24 11:11 UTC | newest]
Thread overview: 9+ messages (download: mbox mbox.gz follow: Atom feed)
-- links below jump to the message on this page --
2008-09-08 23:12 Intel's X25-M SSD Greg Smith <gsmith@gregsmith.com>
2008-09-08 23:59 ` Merlin Moncure <mmoncure@gmail.com>
2008-09-09 15:03 ` Chris Browne <cbbrowne@acm.org>
2008-09-20 03:23 ` Greg Smith <gsmith@gregsmith.com>
2008-09-24 03:24 ` Bruce Momjian <bruce@momjian.us>
2008-09-24 04:25 ` Scott Carey <scott@richrelevance.com>
2008-09-24 11:11 ` Steve Clark <sclark@netwolves.com>
2008-09-09 00:19 ` Scott Carey <scott@richrelevance.com>
2008-09-23 04:48 ` Simon Riggs <simon@2ndQuadrant.com>
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