Is SATA currently unreliable?

[John Smith]

This web site at http://www.ata-atapi.com/ says that SATA is
currently unreliable.

Is SATA really this unreliable?


----------

Extract follows:

<QUOTE>

Serial ATA (or SATA) products that are now shipping and available
in your local computer store may not be the most reliable products.

Testing of SATA products with tools such ATACT program are finding
a variety of problems. These problems are timeout errors, data
compare errors, and strange status errors. These problems are being
reported by a large number of people doing SATA product testing.

Hale's advice at this time is be very careful - make sure you can
return the SATA product your purchased if it does not perform as
you expect.

See the ATACT link above for some ATACT log files showing both
normal testing of a parallel ATA (PATA) drive (no errors!) and
testing of a SATA drive (lots of errors!).

<END QUOTE>

 

[Rita Ä Berkowitz]

This web site at http://www.ata-atapi.com/ says that SATA is
currently unreliable.

Is SATA really this unreliable?

Yes, this is why it is so important to use SCSI when you are building a
system that is going to be used for real world applications. SATA is
presently only used in novelty system that are favored by over-clockers and
the neon light crowd.

Rita

 

[Arno Wagner]

Yes, this is why it is so important to use SCSI when you are building a
system that is going to be used for real world applications. SATA is
presently only used in novelty system that are favored by over-clockers and
the neon light crowd.

That is maybe a bit overstated. But in principle consumer-grade
drives are significantly less reliable than SCSI. With RAID
they are still reliable enough for the real world. However SCSI
is faster in seek-intensive uses (i.e. smaller reads). So if
you need reliability and speed for small accesses, go SCSI.
If cost does not matter much, use SCSI. If cost matters, but
power consumption and noise does not matter do carefully
designed RAID on IDE. If cost, power and noise matter, use
a single Samsung IDE drive and do frequent backups.

I have had recent compatibility isues with SATA and I would say
it is not mature yet. Give it another year or so.

Arno

 

[Joe Brown]

Anything that new never is.

Pathetic excuse for a troll, as always from the Bigotowitz.

That is maybe a bit overstated.

Just a tad.

But in principle consumer-grade drives
are significantly less reliable than SCSI.

Have fun explaining why PATA is fine and SATA aint.

With RAID they are still reliable enough for the real world.

You dont have to use RAID, various other approaches
to real time backup give much more protection against
inevitable failure with any systems.

However SCSI is faster in seek-intensive uses (i.e. smaller reads).
So if you need reliability and speed for small accesses, go SCSI.

And very few actually have seek intensive
apps with personal desktop systems.

If cost does not matter much, use SCSI. If cost
matters, but power consumption and noise does
not matter do carefully designed RAID on IDE.

Or have real time backup that provides a lot more than just RAID.

If cost, power and noise matter, use a single
Samsung IDE drive and do frequent backups.

Only need frequent backups if the data changes much.
It doesnt with most personal desktop systems.

I have had recent compatibility isues with
SATA and I would say it is not mature yet.

Corse it isnt given how long its been buyable for.

 

[dg]

I don't think any statement pertaining to reliability can be made based
solely on the drive interface. I am sure there have been some crappy SCSI
drives made before too, but I wouldn't say that SCSI overall is unreliable
just because some of them are.

--Dan

 

[Rita Ä Berkowitz]

Yes, this is why it is so important to use SCSI when you are building a

That is maybe a bit overstated. But in principle consumer-grade
drives are significantly less reliable than SCSI. With RAID
they are still reliable enough for the real world. However SCSI
is faster in seek-intensive uses (i.e. smaller reads). So if
you need reliability and speed for small accesses, go SCSI.
If cost does not matter much, use SCSI. If cost matters, but
power consumption and noise does not matter do carefully
designed RAID on IDE. If cost, power and noise matter, use
a single Samsung IDE drive and do frequent backups.

I have had recent compatibility isues with SATA and I would say
it is not mature yet. Give it another year or so.

At this point in time I would have to agree with you. I just don't feel the
reliability of SATA is at a point were a "set it and forget it" system can
made using them. I'll give SATA a serious look in a year or so, also.
Maybe they will be developed to the point were SCSI can be abandoned
completely?



Rita

 

[Rita Ä Berkowitz]

I don't think any statement pertaining to reliability can be made based
solely on the drive interface. I am sure there have been some crappy SCSI
drives made before too, but I wouldn't say that SCSI overall is unreliable
just because some of them are.

The statement was made with taking into consideration that, as a whole, SATA
cannot reliably compete with SCSI. Keep in mind that SCSI still overshadows
SATA for performance, function, and reliability. And yes, I too have seen
some real shitty SCSI drives, Western Digital comes to mind.



Rita

 

[Eric Gisin]

The URL is Hale Landis's site. He claims the current implementation of sATA,
host/device/bridge, is flakey and prone to spurious errors. I doubt he means
drive reliability.

 

[Shailesh]

I am using consumer-grade SATA drives on a consumer-grade
motherboard/controller, and they work perfectly fine. So all I can
add is that SATA is not completely unreliable.

That quote doesn't give any real information, so there's no way to
evaluate its truth. Why don't you ask if anyone is currently using a
system with SATA like you intend to build, and then you'll find out if
they had any problems with the SATA part.

 

[Arno Wagner]

At this point in time I would have to agree with you. I just don't feel the
reliability of SATA is at a point were a "set it and forget it" system can
made using them. I'll give SATA a serious look in a year or so, also.
Maybe they will be developed to the point were SCSI can be abandoned
completely?

I don't think so. SCSI has other advantages, like longer cables.
But it is not actually the interface that makes SCSI drives
more reliable. It is the market. (O.k., some problems with the
interface too, like no multi-path I/O in SATA,...). I believe
as soon as the interface is mature it is quite possible to
create SATA drives at SCSI speed, reloability and price levels.
I would like that. But it is unlikely that the "cheap and fast"
crowd will buy these, and the "SCSI crowd" will likely see no
reason to go from a good interface to a potentially good one.

Arno

 

[Dorothy Bradbury]

There are 2 segments, desktop & enterprise:
o Enterprise drive engineering is focused on Reliability + Performance
---- SCSI is chosen for bus bandwidth & multi-drive capability & reliability
o Desktop drives engineering is focused on Cost + Capacity + Appropriate-Reliability
---- ATA/SATA is chosen for chipset cost, cabling cost, appropriate

SATA is a mess by virtue of it being trying to be all things to all people.
o SATA plans on integrating SCSI techniques (TCQ) outside of SAS
---- that's a 20-50% benefit on multi-small-random-access (MS-IE to icon files)
o SATA drives may not however be engineered like SCSI 24/7/365 thrashing
---- so this is a desktop benefit from SCSI-enterprise-filters-down-to-desktop

That said the mkt is moving to smarter use of cheap h/w for certain segments.
o SATA drives are very low cost - but lesser reliability than SCSI
o So combine multiple low-cost drives with 3ware-RAID to get higher reliability

Hence d2d backup servers, NAS, etc using SATA drives.
o Enterprise - if a server goes down, image recovery faster by d2d than tape
o Consumer - WirelessAP differentiate by remote auto-backup file server

The interface is one thing, the mechanical spec of the drive quite another.

The plan seems to be:
o SATA for desktop, SAS for enterprise
---- thus far most 3.5" SATA drives use a bridge to ATA chipset
---- the 2.5" SATA Fujitsu drive I think is the first not to - and adds TCQ
o SATA & SAS use same data cabling & connectors
---- SAS can allow dual porting to the drive for redundancy
o SATA & SAS plan on the same host adapter even, just protocol difference
---- so enterprise with SAS HBA can mix SATA in if required

Only a committee of taxi drivers could come to this objective by this method.

I'd have just created SAS, and dumped SATA.
o Desktop has 1 interface (SAS), but 2 drive standards (Desktop or Enterprise)
o So drive standards defines mechancial reliability/performance
o So drive standard also defines feature-set re TCQ

Instead we have a lot of half-way house offerings.
In the meantime we do have cheap SATA drives for 3ware RAID 12-port boxes,
themselves redundantly arranged to create a good high-speed tape substitute in
terms of fast recovery of data, with tape used for library offlining re access time.

I'm still wondering how the connectors/cabling will scale - and myself waiting to
see how SATA is implemented in 2.5" re side-or-rear-mounted connectors.
Can't the SAS development team just invade the SATA team & regime change?

 

[Alexander Grigoriev]

Well, "Serial SCSI" (or whatever it is called) is supposed to use the same
electrical signalling as SATA (which is very reasonable move). At least no
more bulky expensive cables.

 

[Ron Reaugh]

Yes, this is why it is so important to use SCSI when you are building a
system that is going to be used for real world applications. SATA is
presently only used in novelty system that are favored by over-clockers and
the neon light crowd.

Clueless drivel.

 

[Ron Reaugh]

That is maybe a bit overstated. But in principle consumer-grade
drives are significantly less reliable than SCSI.

Utter nonsense. Cite any real supporting information that assertion.

With RAID
they are still reliable enough for the real world. However SCSI
is faster in seek-intensive uses (i.e. smaller reads).

Only faster in some cases for the most expensive SCSI HDs at 3x the cost of
a fast ATA HD...can you say Raptor.

So if
you need reliability

Then use RAID 5 or RAID 1 etc. whether ATA or SCSI.

and speed for small accesses, go SCSI.
If cost does not matter much, use SCSI.

Yep, but those lightening fast and expensive 15K RPM Fujitsus SCSI HDs.

If cost matters, but
power consumption and noise does not matter do carefully
designed RAID on IDE.

Forget the power consumption and noise false assertions and you got it
right.

If cost, power and noise matter, use
a single Samsung IDE drive and do frequent backups.

I have had recent compatibility isues with SATA and I would say
it is not mature yet. Give it another year or so.

Doesn't need that long. I have a number of SATA Raptors running on W2K3
Servers and they're workin fine.

 

[Ron Reaugh]

-snip

And very few actually have seek intensive
apps with personal desktop systems.

For SCSI to show an advantage it takes more than just seek intensive tasks.
It takes saturating seek intensive tasks such that SCSI's queue of
outstanding IOs grows to the point where SCSI HD's onboard optimizations
actually contribute to throughput. Such a queue depth also means that a
workstation will have to become sluggish(over saturated) to realize the
advantage.

 

[Ron Reaugh]

I don't think any statement pertaining to reliability can be made based
solely on the drive interface.
Yep.

I am sure there have been some crappy SCSI
drives made before too,

Sure have been.

 

[Ron Reaugh]

The statement was made with taking into consideration that, as a whole, SATA
cannot reliably compete with SCSI.

SATA can compete very well indeed in the price performance category. Is
there any other category?

Keep in mind that SCSI still overshadows
SATA for performance, function, and reliability.

You forgot the most important issue. SCSI vastly overshadows SATA in cost.
What's an Adaptec 29320A going for...~$300 and that's a single channel
non-RAID card.

 

[Ron Reaugh]

There are 2 segments, desktop & enterprise:
o Enterprise drive engineering is focused on Reliability + Performance

Cite any source that suggests that actual drive design....heads+actuators,
platters and spindle bearings are technically any different betwen the top
SCSI 'enterprise' drives and SATA drives like the Raptor. You can't because
the technology at any given drive generation is the same and is moving fast.
There aren't TWO fundamental designs.

---- SCSI is chosen for bus bandwidth & multi-drive capability &

reliability

That's interface and controller card stuff and has nothing to do with drive
physics.

o Desktop drives engineering is focused on Cost + Capacity + Appropriate-Reliability
---- ATA/SATA is chosen for chipset cost, cabling cost, appropriate

SATA is a mess by virtue of it being trying to be all things to all

people.

Just no.

o SATA plans on integrating SCSI techniques (TCQ) outside of SAS
---- that's a 20-50% benefit on multi-small-random-access (MS-IE to icon

files)

HUH, only if there are a number of outstanding IOs, which gives a sluggish
workstation but possibly a high performance transaction server. SATA
command overhead is lower giving it an advantage on workstations operated
below IO saturation.

o SATA drives may not however be engineered like SCSI 24/7/365 thrashing
---- so this is a desktop benefit from

SCSI-enterprise-filters-down-to-desktop

The above however is based on wild and false conjecture.

That said the mkt is moving to smarter use of cheap h/w for certain segments.
o SATA drives are very low cost - but lesser reliability than SCSI

There's no indication that good SATA HDs are of lower reliability than SCSI
HDs. Note that the warranty length is NOT an indication of reliability.

o So combine multiple low-cost drives with 3ware-RAID to get higher

reliability

Now you're gettin it.

Hence d2d backup servers, NAS, etc using SATA drives.
o Enterprise - if a server goes down, image recovery faster by d2d than tape

Exactly.

o Consumer - WirelessAP differentiate by remote auto-backup file server

The interface is one thing, the mechanical spec of the drive quite another.

The plan seems to be:
o SATA for desktop, SAS for enterprise
---- thus far most 3.5" SATA drives use a bridge to ATA chipset
---- the 2.5" SATA Fujitsu drive I think is the first not to - and adds

TCQ


Well Seagate, Intel and SiliconImage demo-ed it first.

 

[Ron Reaugh]

Well, "Serial SCSI" (or whatever it is called) is supposed to use the same
electrical signalling as SATA (which is very reasonable move). At least no
more bulky expensive cables.

Damn, I love parallel SCSI cabling and termination issues....I guess mostly
because most don't understand it well....job security and everything ya
know.

 

[Folkert Rienstra]

[Troll snipped]

That is maybe a bit overstated.

But in principle

Nope, no principle involved.

consumer-grade drives are significantly less reliable than SCSI.

Nonsense,
there is enterprise grade SATA and there is consumer grade SCSI too.

With RAID they are still reliable enough for the real world.
However SCSI is faster in seek-intensive uses (i.e. smaller reads).

SCSI also has big overhead on small transfers.