> -----Original Message-----
> From: Alex Turner [mailto:armtuk@gmail.com]
> Sent: Thursday, April 14, 2005 6:15 PM
> To: Dave Held
> Cc: pgsql-performance@postgresql.org
> Subject: Re: [PERFORM] Intel SRCS16 SATA raid?
>
> Looking at the numbers, the raptor with TCQ enabled was close or
> beat the Atlas III 10k drive on most benchmarks.

And I would be willing to bet that the Atlas 10k is not using the
same generation of technology as the Raptors.

> Naturaly a 15k drive is going to be faster in many areas, but it
> is also much more expensive. It was only 44% better on the server
> tests than the raptor with TCQ, but it costs nearly 300% more ($538
> cdw.com, $180 newegg.com).

State that in terms of cars. Would you be willing to pay 300% more
for a car that is 44% faster than your competitor's? Of course you
would, because we all recognize that the cost of speed/performance
does not scale linearly. Naturally, you buy the best speed that you
can afford, but when it comes to hard drives, the only major feature
whose price tends to scale anywhere close to linearly is capacity.

> Note also that the 15k drive was the only drive that kept up with
> the raptor on raw transfer speed, which is going to matter for WAL.

So get a Raptor for your WAL partition.

> [...]
> The Raptor drives can be had for as little as $180/ea, which is
> quite a good price point considering they can keep up with their
> SCSI 10k RPM counterparts on almost all tests with NCQ enabled
> (Note that 3ware controllers _don't_ support NCQ, although they
> claim their HBA based queueing is 95% as good as NCQ on the drive).

Just keep in mind the points made by the Seagate article. You're
buying much more than just performance for that $500+. You're also
buying vibrational tolerance, high MTBF, better internal
environmental controls, and a pretty significant margin on seek time,
which is probably your most important feature for disks storing tables.
An interesting test would be to stick several drives in a cabinet and
graph how performance is affected at the different price points/
technologies/number of drives.

__
David B. Held
Software Engineer/Array Services Group
200 14th Ave. East, Sartell, MN 56377
320.534.3637 320.253.7800 800.752.8129

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Dave wrote "An interesting test would be to stick several drives in a
cabinet and
graph how performance is affected at the different price points/
technologies/number of drives."

From the discussion on the $7k server thread, it seems the RAID controller
would
be an important data point also. And RAID level. And application
load/kind.

Hmmm. I just talked myself out of it. Seems like I'd end up with
something
akin to those database benchmarks we all love to hate.

Rick

pgsql-performance-owner@postgresql.org wrote on 04/15/2005 08:40:13 AM:

> > -----Original Message-----
> > From: Alex Turner [mailto:armtuk@gmail.com]
> > Sent: Thursday, April 14, 2005 6:15 PM
> > To: Dave Held
> > Cc: pgsql-performance@postgresql.org
> > Subject: Re: [PERFORM] Intel SRCS16 SATA raid?
> >
> > Looking at the numbers, the raptor with TCQ enabled was close or
> > beat the Atlas III 10k drive on most benchmarks.
>
> And I would be willing to bet that the Atlas 10k is not using the
> same generation of technology as the Raptors.
>
> > Naturaly a 15k drive is going to be faster in many areas, but it
> > is also much more expensive. It was only 44% better on the server
> > tests than the raptor with TCQ, but it costs nearly 300% more ($538
> > cdw.com, $180 newegg.com).
>
> State that in terms of cars. Would you be willing to pay 300% more
> for a car that is 44% faster than your competitor's? Of course you
> would, because we all recognize that the cost of speed/performance
> does not scale linearly. Naturally, you buy the best speed that you
> can afford, but when it comes to hard drives, the only major feature
> whose price tends to scale anywhere close to linearly is capacity.
>
> > Note also that the 15k drive was the only drive that kept up with
> > the raptor on raw transfer speed, which is going to matter for WAL.
>
> So get a Raptor for your WAL partition.
>
> > [...]
> > The Raptor drives can be had for as little as $180/ea, which is
> > quite a good price point considering they can keep up with their
> > SCSI 10k RPM counterparts on almost all tests with NCQ enabled
> > (Note that 3ware controllers _don't_ support NCQ, although they
> > claim their HBA based queueing is 95% as good as NCQ on the drive).
>
> Just keep in mind the points made by the Seagate article. You're
> buying much more than just performance for that $500+. You're also
> buying vibrational tolerance, high MTBF, better internal
> environmental controls, and a pretty significant margin on seek time,
> which is probably your most important feature for disks storing tables.
> An interesting test would be to stick several drives in a cabinet and
> graph how performance is affected at the different price points/
> technologies/number of drives.
>
> __
> David B. Held
> Software Engineer/Array Services Group
> 200 14th Ave. East, Sartell, MN 56377
> 320.534.3637 320.253.7800 800.752.8129
>
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> message can get through to the mailing list cleanly


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The original thread was how much can I get for $7k

You can't fit a 15k RPM SCSI solution into $7K Some of us are on a budget!

10k RPM SATA drives give acceptable performance at a good price, thats
really the point here.

I have never really argued that SATA is going to match SCSI
performance on multidrive arrays for IO/sec. But it's all about the
benjamins baby. If I told my boss we need $25k for a database
machine, he'd tell me that was impossible, and I have $5k to do it.
If I tell him $7k - he will swallow that. We don't _need_ the amazing
performance of a 15k RPM drive config. Our biggest hit is reads, so
we can buy 3xSATA machines and load balance. It's all about the
application, and buying what is appropriate. I don't buy a Corvette
if all I need is a malibu.

Alex Turner
netEconomist

On 4/15/05, Dave Held <dave.held@arrayservicesgrp.com> wrote:
> > -----Original Message-----
> > From: Alex Turner [mailto:armtuk@gmail.com]
> > Sent: Thursday, April 14, 2005 6:15 PM
> > To: Dave Held
> > Cc: pgsql-performance@postgresql.org
> > Subject: Re: [PERFORM] Intel SRCS16 SATA raid?
> >
> > Looking at the numbers, the raptor with TCQ enabled was close or
> > beat the Atlas III 10k drive on most benchmarks.
>
> And I would be willing to bet that the Atlas 10k is not using the
> same generation of technology as the Raptors.
>
> > Naturaly a 15k drive is going to be faster in many areas, but it
> > is also much more expensive. It was only 44% better on the server
> > tests than the raptor with TCQ, but it costs nearly 300% more ($538
> > cdw.com, $180 newegg.com).
>
> State that in terms of cars. Would you be willing to pay 300% more
> for a car that is 44% faster than your competitor's? Of course you
> would, because we all recognize that the cost of speed/performance
> does not scale linearly. Naturally, you buy the best speed that you
> can afford, but when it comes to hard drives, the only major feature
> whose price tends to scale anywhere close to linearly is capacity.
>
> > Note also that the 15k drive was the only drive that kept up with
> > the raptor on raw transfer speed, which is going to matter for WAL.
>
> So get a Raptor for your WAL partition.
>
> > [...]
> > The Raptor drives can be had for as little as $180/ea, which is
> > quite a good price point considering they can keep up with their
> > SCSI 10k RPM counterparts on almost all tests with NCQ enabled
> > (Note that 3ware controllers _don't_ support NCQ, although they
> > claim their HBA based queueing is 95% as good as NCQ on the drive).
>
> Just keep in mind the points made by the Seagate article. You're
> buying much more than just performance for that $500+. You're also
> buying vibrational tolerance, high MTBF, better internal
> environmental controls, and a pretty significant margin on seek time,
> which is probably your most important feature for disks storing tables.
> An interesting test would be to stick several drives in a cabinet and
> graph how performance is affected at the different price points/
> technologies/number of drives.
>
> __
> David B. Held
> Software Engineer/Array Services Group
> 200 14th Ave. East, Sartell, MN 56377
> 320.534.3637 320.253.7800 800.752.8129
>
> ---------------------------(end of broadcast)---------------------------
> TIP 3: if posting/reading through Usenet, please send an appropriate
> subscribe-nomail command to majordomo@postgresql.org so that your
> message can get through to the mailing list cleanly
>

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This is a different thread that the $7k server thread.
Greg Stark started it and wrote:

"I'm also wondering about whether I'm better off with one of these
SATA raid
controllers or just going with SCSI drives."



Rick

pgsql-performance-owner@postgresql.org wrote on 04/15/2005 10:01:56 AM:

> The original thread was how much can I get for $7k
>
> You can't fit a 15k RPM SCSI solution into $7K Some of us are ona
budget!
>
> 10k RPM SATA drives give acceptable performance at a good price, thats
> really the point here.
>
> I have never really argued that SATA is going to match SCSI
> performance on multidrive arrays for IO/sec. But it's all about the
> benjamins baby. If I told my boss we need $25k for a database
> machine, he'd tell me that was impossible, and I have $5k to do it.
> If I tell him $7k - he will swallow that. We don't _need_ the amazing
> performance of a 15k RPM drive config. Our biggest hit is reads, so
> we can buy 3xSATA machines and load balance. It's all about the
> application, and buying what is appropriate. I don't buy a Corvette
> if all I need is a malibu.
>
> Alex Turner
> netEconomist
>
> On 4/15/05, Dave Held <dave.held@arrayservicesgrp.com> wrote:
> > > -----Original Message-----
> > > From: Alex Turner [mailto:armtuk@gmail.com]
> > > Sent: Thursday, April 14, 2005 6:15 PM
> > > To: Dave Held
> > > Cc: pgsql-performance@postgresql.org
> > > Subject: Re: [PERFORM] Intel SRCS16 SATA raid?
> > >
> > > Looking at the numbers, the raptor with TCQ enabled was close or
> > > beat the Atlas III 10k drive on most benchmarks.
> >
> > And I would be willing to bet that the Atlas 10k is not using the
> > same generation of technology as the Raptors.
> >
> > > Naturaly a 15k drive is going to be faster in many areas, but it
> > > is also much more expensive. It was only 44% better on the server
> > > tests than the raptor with TCQ, but it costs nearly 300% more ($538
> > > cdw.com, $180 newegg.com).
> >
> > State that in terms of cars. Would you be willing to pay 300% more
> > for a car that is 44% faster than your competitor's? Of course you
> > would, because we all recognize that the cost of speed/performance
> > does not scale linearly. Naturally, you buy the best speed that you
> > can afford, but when it comes to hard drives, the only major feature
> > whose price tends to scale anywhere close to linearly is capacity.
> >
> > > Note also that the 15k drive was the only drive that kept up with
> > > the raptor on raw transfer speed, which is going to matter for WAL.
> >
> > So get a Raptor for your WAL partition.
> >
> > > [...]
> > > The Raptor drives can be had for as little as $180/ea, which is
> > > quite a good price point considering they can keep up with their
> > > SCSI 10k RPM counterparts on almost all tests with NCQ enabled
> > > (Note that 3ware controllers _don't_ support NCQ, although they
> > > claim their HBA based queueing is 95% as good as NCQ on the drive).
> >
> > Just keep in mind the points made by the Seagate article. You're
> > buying much more than just performance for that $500+. You're also
> > buying vibrational tolerance, high MTBF, better internal
> > environmental controls, and a pretty significant margin on seek time,
> > which is probably your most important feature for disks storing tables.
> > An interesting test would be to stick several drives in a cabinet and
> > graph how performance is affected at the different price points/
> > technologies/number of drives.
> >
> > __
> > David B. Held
> > Software Engineer/Array Services Group
> > 200 14th Ave. East, Sartell, MN 56377
> > 320.534.3637 320.253.7800 800.752.8129
> >
> > ---------------------------(end of
broadcast)---------------------------
> > TIP 3: if posting/reading through Usenet, please send an appropriate
> > subscribe-nomail command to majordomo@postgresql.org so that your
> > message can get through to the mailing list cleanly
> >
>
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I stand corrected!

Maybe I should re-evaluate our own config!

Alex T

(The dell PERC controllers do pretty much suck on linux)

On 4/15/05, Vivek Khera <vivek@khera.org> wrote:
>
> On Apr 15, 2005, at 11:01 AM, Alex Turner wrote:
>
> > You can't fit a 15k RPM SCSI solution into $7K Some of us are on a
> > budget!
> >
>
> I just bought a pair of Dual Opteron, 4GB RAM, LSI 320-2X RAID dual
> channel with 8 36GB 15kRPM seagate drives. Each one of these boxes set
> me back just over $7k, including onsite warrantee.
>
> They totally blow away the Dell Dual XEON with external 14 disk RAID
> (also 15kRPM drives, manufacturer unknown) which also has 4GB RAM and a
> Dell PERC 3/DC controller, the whole of which set me back over $15k.
>
> Vivek Khera, Ph.D.
> +1-301-869-4449 x806
>
>
>

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