SCSI or SATA

We want to make some drastic maintenance at our server system. So far of
course only SCSI drives were recomended.

I am now not too sure if we shall consider SATA drives. They are much
cheaper and the speed is compareblae to SCSI drives. Is this true and is
really recommended?

Marek Staniewski

SuperGumby
Fri Sep 16 16:50:15 CDT 2005

there are two (or more) significant performance differentiators between SCSI
and SATA, the rotational speed of the drives and support of Native Command
Queueing. I'm leaving the interface rate out of it, interface speeds are
set.

I just checked a local distributor.
All available SCSI drives are 10Krpm or better (15K). The Western Digital
Raptors are the only SATA drive they stock with a 10K rotational speed.

Native Command Queueing on SATA drives is a bit hit and miss (AFAIK, gotta
admit to not a lot of experience here). From what I read it will depend on
the combination of controller and drive. Of course, SCSI has had this for a
long time and it is quite flexible. NCC assists, particularly in busy
multitasking systems like SBS, by rearranging the order of reads/writes to
the disk, minimising head travel. This not only increases the real world
throughput of the drive but reduces head movement and therefore wear and
tear on the actuator at least theoretically increasing the life of the
drive.

Look at the quoted MTBF figures for the drives. The Raptors mentioned above
quote very similar MTBF figures to SCSI drives, most other SATA have much
lower figures. This is reflected in the warranty offered on the drives, most
SATA having 1yr warranty, some having 3yr, few having 5yr. I'm not saying
warranty directly corresponds to better drives.

I recently inherited support of several SBS systems using SATA drives, most
using Intel Dual Xeon mobo's with builtin SII RAID1. They all perform like
dogs.

"Marek Staniewski" <remove-it.marek.staniewski@derco.com.pl> wrote in
message news:u%23LdyPuuFHA.2312@TK2MSFTNGP14.phx.gbl...
> We want to make some drastic maintenance at our server system. So far of
> course only SCSI drives were recomended.
>
> I am now not too sure if we shall consider SATA drives. They are much
> cheaper and the speed is compareblae to SCSI drives. Is this true and is
> really recommended?
>
> Marek Staniewski
>
>

Duncan
Fri Sep 16 19:24:07 CDT 2005

In article <OhpMhiwuFHA.1472@TK2MSFTNGP15.phx.gbl>, not@your.nellie
says...
> there are two (or more) significant performance differentiators between SCSI
> and SATA, the rotational speed of the drives and support of Native Command
> Queueing. I'm leaving the interface rate out of it, interface speeds are
> set.

About SATA, do they support hot swapping?

--
Duncan

Michael
Fri Sep 16 21:35:12 CDT 2005

Other item to consider is the Mean time before failure. Allot of SATA
resellers are selling workstation drives that appear highspeed but not
designed to run 24x7. Serial attached SCSI is now out so new
technologies are just appearing that might be more appropriate.


Duncan McC wrote:

> In article <OhpMhiwuFHA.1472@TK2MSFTNGP15.phx.gbl>, not@your.nellie
> says...
> > there are two (or more) significant performance differentiators between SCSI
> > and SATA, the rotational speed of the drives and support of Native Command
> > Queueing. I'm leaving the interface rate out of it, interface speeds are
> > set.
>
> About SATA, do they support hot swapping?
>
>

--
Michael J. Jenkin MVP - SBS, Senior Systems Engineer
Visit http://www.mickyj.com

Microsoft Most Valued Professional, Microsoft's Windows Server Systems -
Small Business Server
MVP's do not work for Microsoft. If this email was generated in a
newsgroup, please reply only to the newsgroup.
Note: The contents of my postings and responses here represent my
personal opinions and do not necessarily reflect the views, thoughts or
feelings of Microsoft or any of its employees.
http://mvp.support.microsoft.com

Michael
Fri Sep 16 21:38:18 CDT 2005

If you have the money, you can buy the hotswap drive bays. You might
also need to look into a special Sata controller.

Take a look at a few
http://www.google.com.au/search?hl=en&q=hot+swap+sata+drives&meta=


Duncan McC wrote:

> In article <OhpMhiwuFHA.1472@TK2MSFTNGP15.phx.gbl>, not@your.nellie
> says...
> > there are two (or more) significant performance differentiators between SCSI
> > and SATA, the rotational speed of the drives and support of Native Command
> > Queueing. I'm leaving the interface rate out of it, interface speeds are
> > set.
>
> About SATA, do they support hot swapping?
>
>

--
Michael J. Jenkin MVP - SBS, Senior Systems Engineer
Visit http://www.mickyj.com

Microsoft Most Valued Professional, Microsoft's Windows Server Systems -
Small Business Server
MVP's do not work for Microsoft. If this email was generated in a
newsgroup, please reply only to the newsgroup.
Note: The contents of my postings and responses here represent my
personal opinions and do not necessarily reflect the views, thoughts or
feelings of Microsoft or any of its employees.
http://mvp.support.microsoft.com

Pat
Tue Sep 20 06:53:05 CDT 2005


"Duncan McC" <hard@work.ok> wrote in message
news:MPG.1d962955faad9cb39897d7@news.microsoft.com...
> In article <OhpMhiwuFHA.1472@TK2MSFTNGP15.phx.gbl>, not@your.nellie
> says...
>> there are two (or more) significant performance differentiators between
>> SCSI
>> and SATA, the rotational speed of the drives and support of Native
>> Command
>> Queueing. I'm leaving the interface rate out of it, interface speeds are
>> set.
>
> About SATA, do they support hot swapping?
>
> --
> Duncan

I believe they can it depends upon the bay they are installed in and the
controller connected to them.

Duncan
Tue Sep 20 22:50:10 CDT 2005

In article <dgot6q$cf5$1$8302bc10@news.demon.co.uk>, pat@remove-
spam.vet.co.uk says...
>
> "Duncan McC" <hard@work.ok> wrote in message
> news:MPG.1d962955faad9cb39897d7@news.microsoft.com...
> > In article <OhpMhiwuFHA.1472@TK2MSFTNGP15.phx.gbl>, not@your.nellie
> > says...
> >> there are two (or more) significant performance differentiators between
> >> SCSI
> >> and SATA, the rotational speed of the drives and support of Native
> >> Command
> >> Queueing. I'm leaving the interface rate out of it, interface speeds are
> >> set.
> >
> > About SATA, do they support hot swapping?
> >
> > --
> > Duncan
>
> I believe they can it depends upon the bay they are installed in and the
> controller connected to them.

Thanks, I thought that might be the case - so pretty much the same as
SCSI ('cept there may not be that many hot-swappable controllers for
SATA drives out there - yet.)

--
Duncan

WendelHamilton
Sun Sep 25 07:44:07 CDT 2005

Seagate offer SATA drives with 5 years warranty.
Adaptec have SATA raid controllers so do Intel and others.
Enlight have SATA hot swap bays.
I have a mixture of customers using SATA RAID and SCSI RAID and in terms of
drive failures I've replaced dozens of SCSI drives but only 1 SATA this if
probably because of the high power requirements of SCSI drives.
While drive rotation latency can be an issue with SATA itâ??s mostly over come
with large read cache in the drive and controllers. If you need that extra
10-20% performance then SCSI is the way to go but honestly unless you are
serving huge databases or hosting 1000s of exchange mailboxes SATA is worth a
go.

"Duncan McC" wrote:

> In article <dgot6q$cf5$1$8302bc10@news.demon.co.uk>, pat@remove-
> spam.vet.co.uk says...
> >
> > "Duncan McC" <hard@work.ok> wrote in message
> > news:MPG.1d962955faad9cb39897d7@news.microsoft.com...
> > > In article <OhpMhiwuFHA.1472@TK2MSFTNGP15.phx.gbl>, not@your.nellie
> > > says...
> > >> there are two (or more) significant performance differentiators between
> > >> SCSI
> > >> and SATA, the rotational speed of the drives and support of Native
> > >> Command
> > >> Queueing. I'm leaving the interface rate out of it, interface speeds are
> > >> set.
> > >
> > > About SATA, do they support hot swapping?
> > >
> > > --
> > > Duncan
> >
> > I believe they can it depends upon the bay they are installed in and the
> > controller connected to them.
>
> Thanks, I thought that might be the case - so pretty much the same as
> SCSI ('cept there may not be that many hot-swappable controllers for
> SATA drives out there - yet.)
>
> --
> Duncan
>

WendelHamilton
Sun Sep 25 07:49:05 CDT 2005

Oh I should have mentioned that if you are going to use SATA only use RAID 5
configuration as Raid 0,1 really do cripple their performance.

"Duncan McC" wrote:

> In article <dgot6q$cf5$1$8302bc10@news.demon.co.uk>, pat@remove-
> spam.vet.co.uk says...
> >
> > "Duncan McC" <hard@work.ok> wrote in message
> > news:MPG.1d962955faad9cb39897d7@news.microsoft.com...
> > > In article <OhpMhiwuFHA.1472@TK2MSFTNGP15.phx.gbl>, not@your.nellie
> > > says...
> > >> there are two (or more) significant performance differentiators between
> > >> SCSI
> > >> and SATA, the rotational speed of the drives and support of Native
> > >> Command
> > >> Queueing. I'm leaving the interface rate out of it, interface speeds are
> > >> set.
> > >
> > > About SATA, do they support hot swapping?
> > >
> > > --
> > > Duncan
> >
> > I believe they can it depends upon the bay they are installed in and the
> > controller connected to them.
>
> Thanks, I thought that might be the case - so pretty much the same as
> SCSI ('cept there may not be that many hot-swappable controllers for
> SATA drives out there - yet.)
>
> --
> Duncan
>

Duncan
Sun Sep 25 08:43:11 CDT 2005

In article <E27FC5A6-1836-484A-B235-207884C9A52E@microsoft.com>,
WendelHamilton@discussions.microsoft.com says...
> Oh I should have mentioned that if you are going to use SATA only use RAID 5
> configuration as Raid 0,1 really do cripple their performance.

How do you work that out?

--
Duncan

SuperGumby
Mon Oct 03 14:32:56 CDT 2005

me suggesting something "...perform like dogs"? should not be taken as a
positive comment.

basically, I reckon SATA is workstation technology.

"Marek Staniewski" <remove-it.marek.staniewski@derco.com.pl> wrote in
message news:%23i1Aqf1xFHA.2652@TK2MSFTNGP14.phx.gbl...
> Can someone tell me what means the expression "...perform like dogs"? Is
> this a positive meaning or negative meaning (see text bellow).
>
> Marek Staniewski
>
>
> U¿ytkownik "SuperGumby [SBS MVP]" <not@your.nellie> napisa³ w wiadomo¶ci
> news:OhpMhiwuFHA.1472@TK2MSFTNGP15.phx.gbl...
>> there are two (or more) significant performance differentiators between
>> SCSI and SATA, the rotational speed of the drives and support of Native
>> Command Queueing. I'm leaving the interface rate out of it, interface
>> speeds are set.
>>
>> I just checked a local distributor.
>> All available SCSI drives are 10Krpm or better (15K). The Western Digital
>> Raptors are the only SATA drive they stock with a 10K rotational speed.
>>
>> Native Command Queueing on SATA drives is a bit hit and miss (AFAIK,
>> gotta admit to not a lot of experience here). From what I read it will
>> depend on the combination of controller and drive. Of course, SCSI has
>> had this for a long time and it is quite flexible. NCC assists,
>> particularly in busy multitasking systems like SBS, by rearranging the
>> order of reads/writes to the disk, minimising head travel. This not only
>> increases the real world throughput of the drive but reduces head
>> movement and therefore wear and tear on the actuator at least
>> theoretically increasing the life of the drive.
>>
>> Look at the quoted MTBF figures for the drives. The Raptors mentioned
>> above quote very similar MTBF figures to SCSI drives, most other SATA
>> have much lower figures. This is reflected in the warranty offered on the
>> drives, most SATA having 1yr warranty, some having 3yr, few having 5yr.
>> I'm not saying warranty directly corresponds to better drives.
>>
>> I recently inherited support of several SBS systems using SATA drives,
>> most using Intel Dual Xeon mobo's with builtin SII RAID1. They all
>> perform like dogs.
>>
>> "Marek Staniewski" <remove-it.marek.staniewski@derco.com.pl> wrote in
>> message news:u%23LdyPuuFHA.2312@TK2MSFTNGP14.phx.gbl...
>>> We want to make some drastic maintenance at our server system. So far of
>>> course only SCSI drives were recomended.
>>>
>>> I am now not too sure if we shall consider SATA drives. They are much
>>> cheaper and the speed is compareblae to SCSI drives. Is this true and is
>>> really recommended?
>>>
>>> Marek Staniewski
>>>
>>>
>>
>>
>
>