Is SATA currently unreliable?

[Rita Ä Berkowitz]

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.

Yeah, Rod, it takes a lot of skill to send a SCSI ID, and terminate the last
device in the chain.

Rita

 

[Rita Ä Berkowitz]

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

Yes, Rod, reliability. I guess if you need a system you can depend on, a
few extra bucks up front will save loads of money, prevent lost data and
productivity you would want the reliability of SCSI.

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.

Again, if your data, time, and personal are worthless and easily replaceable
than you can go with the SATA novelty to save a few pennies up front..



Rita

 

[Rita Ä Berkowitz]

Clueless drivel.

Of course it is, Rod.

Rita

 

[Ron Reaugh]

least
Yeah, Rod, it takes a lot of skill to send a SCSI ID, and terminate the last
device in the chain.

Another one I see.

I sure that you meant to say terminate both physical ends of the cable.
Termination has nothing to do with devices except that in SE SCSI on a
device was frequently a convenient place to locate a terminator. Tell us
all about the terminators onboard LVD HDs, why don't ya??

You gotta understand SCSI terminology a little better as there's ambiguity
between the "chain" and the "cable". How many terminations are there on a
SCSI 'chain' that includes a bridge chip(like Adaptec's) where there's an SE
cable section and a LVD cable section? What about an SE cable with a narrow
section and a wide section; do ya know where all the terminations go?

 

[Ron Reaugh]

Yes, Rod, reliability. I guess if you need a system you can depend on, a
few extra bucks up front will save loads of money, prevent lost data and
productivity you would want the reliability of SCSI.

Now say it aloud...price performance.

 

[Rita Ä Berkowitz]

Another one I see.

I sure that you meant to say terminate both physical ends of the cable.
Termination has nothing to do with devices except that in SE SCSI on a
device was frequently a convenient place to locate a terminator. Tell us
all about the terminators onboard LVD HDs, why don't ya??

Rod, I think we both know the deal with LVDs? But, I'll let you figure that
one out if you're not sure. If you want to make SCSI sound so difficult
you'll have to try harder. Any moron, even you, has enough sense to read
the manual for the correct jumper settings that come with any SCSI or IDE
drive if they never handled a drive before.. And if they are using "LVD"
drives they will easily figure out where the terminator goes.

You gotta understand SCSI terminology a little better as there's ambiguity
between the "chain" and the "cable". How many terminations are there on a
SCSI 'chain' that includes a bridge chip(like Adaptec's) where there's an SE
cable section and a LVD cable section? What about an SE cable with a narrow
section and a wide section; do ya know where all the terminations go?

What's there to understand? You want to make it sound more complicated than
it really is. If you're not sure RTFM.



Rita

 

[Rita Ä Berkowitz]

SATA can compete very well indeed in the price performance category.
Is

Now say it aloud...price performance.

Yes, you are correct. I forgot that the few pennies I saved using SATA I
could buy more neon lights, chrome fan covers, fans with pretty red and blue
LEDs in them, and a liquid cooler for my overclocked AMD. Thanks for the
correction, Rod, I now see the light and will start peddling novelty PCs.
When the customer calls bitching that he lost his data I can at least tell
him that he has a pretty "state of the art" box.



Rita

 

[Ron Reaugh]

on,

Yes, you are correct. I forgot that the few pennies I saved using SATA I
could buy more neon lights, chrome fan covers, fans with pretty red and blue
LEDs in them, and a liquid cooler for my overclocked AMD. Thanks for the
correction, Rod, I now see the light and will start peddling novelty PCs.
When the customer calls bitching that he lost his data I can at least tell
him that he has a pretty "state of the art" box.

Trolls are slow learners...Now say it aloud.....price performance.

 

[Ron Reaugh]

I thought so...you don't know.

Rod, I think we both know the deal with LVDs? But, I'll let you figure that
one out if you're not sure. If you want to make SCSI sound so difficult
you'll have to try harder. Any moron, even you, has enough sense to read
the manual for the correct jumper settings that come with any SCSI or IDE
drive if they never handled a drive before.. And if they are using "LVD"
drives they will easily figure out where the terminator goes.

an
What's there to understand? You want to make it sound more complicated than
it really is. If you're not sure RTFM.



Rita

 

[Dorothy Bradbury]

There are 2 segments, desktop & enterprise:

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.

There aren't TWO fundamental designs.

Seagate claim TWO fundamental drive design segments:
o Proceedings of 2nd Annual Conference on File & Storage Technology (FAST)
o March 2003
o Seagate Whitepaper
http://www.seagate.com/content/docs/pdf/whitepaper/D2c_More_than_Interface_ATA_vs_SCSI_042003.pdf

It details a host of engineering differences between desktop & enterprise class drives.

o TWO fundamental designs - Enterprise & Desktop
o Enterprise drives are mechanically different to Desktop drives
---- Enterprise *drives* target higher reliability & performance
---- Desktop *drives* target higher capacity & cost competitive
o Drive application segment goes *beyond* interface
---- Raptor = Enterprise segment, Cheetah = Enterprise segment
---- former uses SATA, latter SCSI - *both* are Enterprise segment

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 What's a "good" SATA? A Raptor 10,000rpm? Well that's an Enterprise drive.
o What's a SCSI HD? A Cheetah 10,000rpm? Well that's an Enterprise drive.

Distinction is the *drive design* segment - enterprise or desktop.

Indeed drive design segment is spreading into the 2.5" market:
o Hitachi now produce an enterprise class & laptop class 2.5" 7200rpm HD
o Enterprise class (EK) version = continual use rated, laptop class = is not

The above however is based on wild and false conjecture.

No, it's based on two points:
1) Two drive design segments exist
---- Desktop & Enterprise
2) Current *market offerings* bias the former - at the moment
---- most SATA drives are desktop drives - irrespective of the interface
---- some SATA drives are *enterprise drives* - irrespective of the interface
-------- a Raptor is a *drive* designed for enterprise use
---- most SCSI drives are enterprise drives - irrespective of the interface

Seagate's point - and WD with Raptor - is that Drive-Design-Differs:
o Yes the Raptor has an SATA *interface*
o However the Raptor is an *Enterprise drive* in terms of design

A potential problem is in the implementation of a SATA system:
o SATA Desktop solutions exist - Highpoint
o SATA Enterprise solutions exist - 3ware

SATA or SCSI alone doesn't mean delineate Enterprise or Desktop.
That ignores the cost:benefit of Raptor + 3ware = cheap multi-TB.
o Raptor doesn't win just because of Cheap + Multi-GB + SATA
o Raptor wins because it is Enterprise-Class *as well* = Substitution

SATA drives may not be engineered like SCSI - you have to compare
underlying drive technology re apples to apples, enterprise to enterprise.

o The interface doesn't determine the class of drive
o The design of the drive determines its class

Ok, some will still argue SCSI is a superior enterprise interface to SATA.
That is likely to be a depreciating argument - as SATA & mkt offerings change.

I do think SATA is a mess - but mainly from the low-end implementation:
o Desktop ATA drives using a SATA bridge chip
o Desktop ATA controllers which are just that - desktop use
o SATA connectors aren't well latching
o SATA should have launched with multi-drives per channel

SATA *was* urgently needed - as anyone who has implemented 18" ATA
cable length limits with an 8-port 3ware card re routing & drive-bay distance.
Enterprise can come in a SATA interface - Raptor & 3ware prove it.

I hope that's clearer - there *is* a desktop v enterprise drive design difference.
Most SATA drives are *desktop drives*, Raptor is an *enterprise drive*.

Ok, perhaps Seagate are lying their ass off and we've been overpaying thro
the nose for years for Enterprise class drives which were the same as Desktop.
Perhaps, however enterprise drives seem to outlast desktop in the same task.
Therein is the marketing & engineering win for Raptor over other SATA drives.

 

[Dorothy Bradbury]

Important to distinguish between consumer & enterprise.

SATA seems to be getting slated as much re consumer solutions:
o Consumer -- Highpoint SATA RAID & cheap SATA desktop drive
o Enterprise -- 3ware SATA RAID & Raptor SATA enterprise drive

The gap isn't so much SATA, as the solutions chosen within that interface.

Considering a lot of consumers want 2-port data RAID-1 or RAID-0,
I still wonder why they don't pay the bit extra for 3ware over Highpoint.

 

[Ron Reaugh]

Seagate claim TWO fundamental drive design segments:
o Proceedings of 2nd Annual Conference on File & Storage Technology (FAST)
o March 2003
o Seagate Whitepaper

http://www.seagate.com/content/docs/pdf/whitepaper/D2c_More_than_Interface_ATA_vs_SCSI_042003.pdf

First of all let's look at the title of the paper:
"More than an interface - SCSI vs. ATA"

That belies the distinction you suggest below between Enterprise and
desktop/consumer. This paper is about ATA vs SCSI. SCSI is a big markup
item for the mfgs and they try to protect their profit margins with pure
hype. The first sentence noted below simply confirms my assertion. My
information comes from within a drive design group but not Seagate.

"This paper sets out to clear up a misconception prominent in
the storage community today, that SCSI disc drives and IDE
(ATA) disc drives are the same technology internally, and
differ only in their external interface and in their suggested
retail price. The two classes of drives represent two different
product lines aimed at two different markets."

"...the manufacturing and testing process..."

There may in fact be some differences here but wont affect drive reliability
in the far field..

"A Smart city coupe from DaimlerChrysler is much different than a Mercedes
E-class
sedan,..."

The clincher. This paper has nothing to do with engineering and science but
is a marketing paper built on this kind of crap.

"The most important quality in PS drives is that a drive have a
cost commensurate with the cost of the system in which it is
installed. The cost pressure of the personal computer market
gave rise to the first low-cost hard discs, and has continued
to put pressure on PS drive pricing. As we discuss PS drives,
we will come back to this point repeatedly: low cost dominates
the design of PS drives."

This point is quite correct. It's all about cost and keeping up with the
competition and sales volume. It's a RPM, platter density, noise, head
data channel data rate and heat race. Reliability is a fundamental
prerequirement. All this goes into why that are NOT two fundamental designs
at a given RPM and drive generation.

"ES drives tend to
drive costly innovation - achieving new levels of performance,
reliability or function - and PS drives adopt that technology
when it becomes cheap enough."

True. There are 15K RPM SCSI enterprise drives. There are not 15K RPM SATA
drives. HOWEVER the issue is same generation SCSI 10K RPM vs SATA 10K RPM.
There the differences disappear primarily.

"When one drive is trying to seek or
simply stay on track while nearby drives are spinning, there
is an energy transfer, known as rotational vibration, from
one seeking drive to the other drives in the cabinet."

A red herring issue for recent generation drives. This is something from 5
years ago and before and not currently relevant.

So enough. Anyone can go and read the paper carefully and see that it's
basically marketing crap.

It details a host of engineering differences between desktop & enterprise class drives.

o TWO fundamental designs - Enterprise & Desktop
o Enterprise drives are mechanically different to Desktop drives
---- Enterprise *drives* target higher reliability & performance
---- Desktop *drives* target higher capacity & cost competitive
o Drive application segment goes *beyond* interface
---- Raptor = Enterprise segment, Cheetah = Enterprise segment
---- former uses SATA, latter SCSI - *both* are Enterprise segment



o What's a "good" SATA? A Raptor 10,000rpm? Well that's an Enterprise drive.
o What's a SCSI HD? A Cheetah 10,000rpm? Well that's an Enterprise drive.

Just names based not on technology nor science but only marketing and price
point.

Distinction is the *drive design* segment - enterprise or desktop.

Indeed drive design segment is spreading into the 2.5" market:
o Hitachi now produce an enterprise class & laptop class 2.5" 7200rpm HD
o Enterprise class (EK) version = continual use rated, laptop class = is

not


Right, they simply name it differently and give the enterprise version a
longer warranty and charge bigger bucks...that's mostly it.

No, it's based on two points:
1) Two drive design segments exist
---- Desktop & Enterprise

Nope.

2) Current *market offerings* bias the former - at the moment
---- most SATA drives are desktop drives - irrespective of the interface
---- some SATA drives are *enterprise drives* - irrespective of the interface
-------- a Raptor is a *drive* designed for enterprise use
---- most SCSI drives are enterprise drives - irrespective of the interface

Seagate's point - and WD with Raptor - is that Drive-Design-Differs:
o Yes the Raptor has an SATA *interface*
o However the Raptor is an *Enterprise drive* in terms of design

Nope, only in terms of name. HOWEVER WDC has chosen to both describe the
drive as "enterprise" AND price it at comsumer/desktop levels. That sends
shivers down the back of the SCSI HD market.

A potential problem is in the implementation of a SATA system:
o SATA Desktop solutions exist - Highpoint
o SATA Enterprise solutions exist - 3ware

SATA or SCSI alone doesn't mean delineate Enterprise or Desktop.
That ignores the cost:benefit of Raptor + 3ware = cheap multi-TB.
o Raptor doesn't win just because of Cheap + Multi-GB + SATA
o Raptor wins because it is Enterprise-Class *as well* = Substitution
Huh?

SATA drives may not be engineered like SCSI - you have to compare
underlying drive technology re apples to apples, enterprise to enterprise.

Now, you're beginning to get it.

o The interface doesn't determine the class of drive
o The design of the drive determines its class

Now, you're beginning to get it.

Ok, some will still argue SCSI is a superior enterprise interface to SATA.

And it IS for some configurations.

That is likely to be a depreciating argument - as SATA & mkt offerings change.

I do think SATA is a mess - but mainly from the low-end implementation:
o Desktop ATA drives using a SATA bridge chip
o Desktop ATA controllers which are just that - desktop use
o SATA connectors aren't well latching
o SATA should have launched with multi-drives per channel

SATA *was* urgently needed - as anyone who has implemented 18" ATA
cable length limits with an 8-port 3ware card re routing & drive-bay distance.
Enterprise can come in a SATA interface - Raptor & 3ware prove it.

I hope that's clearer - there *is* a desktop v enterprise drive design difference.
Most SATA drives are *desktop drives*, Raptor is an *enterprise drive*.

Rethink what you're saying. Do you work for a HD mfg?

Ok, perhaps Seagate are lying their ass off and we've been overpaying thro
the nose for years for Enterprise class drives which were the same as

Desktop.

Nope, they weren't the same. They were SCSI and they were offered with a
longer warranty and they were produced in lower volume. The hype occurred
when the SCSI HD zealots oversold the advantages of SCSI and projected them
into small/modest server and highend workstation environments. There SCSI
often is NOT the best price performance solution. That became apparent over
three years ago. Some of the old wives' tales continue to hold on.

 

[Ron Reaugh]

Important to distinguish between consumer & enterprise.

Yes but do so accurately. See my other post.

SATA seems to be getting slated as much re consumer solutions:
o Consumer -- Highpoint SATA RAID & cheap SATA desktop drive
o Enterprise -- 3ware SATA RAID & Raptor SATA enterprise drive

The gap isn't so much SATA, as the solutions chosen within that interface.

Why does the above sound convoluted and like double talk?

Considering a lot of consumers want 2-port data RAID-1 or RAID-0,
I still wonder why they don't pay the bit extra for 3ware over Highpoint.

Huh? Check the prices. There are very good solutions from Promise and
Intel ICH5R and SiliconImage.

 

[Rita Ä Berkowitz]

Seagate claim TWO fundamental drive design segments:
o Proceedings of 2nd Annual Conference on File & Storage Technology (FAST)
o March 2003
o Seagate Whitepaper
http://www.seagate.com/content/docs/pdf/whitepaper/D2c_More_than_Interface_ATA_vs_SCSI_042003.pdf

It details a host of engineering differences between desktop & enterprise class drives.

o TWO fundamental designs - Enterprise & Desktop
o Enterprise drives are mechanically different to Desktop drives
---- Enterprise *drives* target higher reliability & performance
---- Desktop *drives* target higher capacity & cost competitive
o Drive application segment goes *beyond* interface
---- Raptor = Enterprise segment, Cheetah = Enterprise segment
---- former uses SATA, latter SCSI - *both* are Enterprise segment



o What's a "good" SATA? A Raptor 10,000rpm? Well that's an Enterprise drive.
o What's a SCSI HD? A Cheetah 10,000rpm? Well that's an Enterprise drive.

Distinction is the *drive design* segment - enterprise or desktop.

Indeed drive design segment is spreading into the 2.5" market:
o Hitachi now produce an enterprise class & laptop class 2.5" 7200rpm HD
o Enterprise class (EK) version = continual use rated, laptop class = is not

No, it's based on two points:
1) Two drive design segments exist
---- Desktop & Enterprise
2) Current *market offerings* bias the former - at the moment
---- most SATA drives are desktop drives - irrespective of the interface
---- some SATA drives are *enterprise drives* - irrespective of the interface
-------- a Raptor is a *drive* designed for enterprise use
---- most SCSI drives are enterprise drives - irrespective of the interface

Seagate's point - and WD with Raptor - is that Drive-Design-Differs:
o Yes the Raptor has an SATA *interface*
o However the Raptor is an *Enterprise drive* in terms of design

A potential problem is in the implementation of a SATA system:
o SATA Desktop solutions exist - Highpoint
o SATA Enterprise solutions exist - 3ware

SATA or SCSI alone doesn't mean delineate Enterprise or Desktop.
That ignores the cost:benefit of Raptor + 3ware = cheap multi-TB.
o Raptor doesn't win just because of Cheap + Multi-GB + SATA
o Raptor wins because it is Enterprise-Class *as well* = Substitution

SATA drives may not be engineered like SCSI - you have to compare
underlying drive technology re apples to apples, enterprise to enterprise.

o The interface doesn't determine the class of drive
o The design of the drive determines its class

Ok, some will still argue SCSI is a superior enterprise interface to SATA.
That is likely to be a depreciating argument - as SATA & mkt offerings change.

I do think SATA is a mess - but mainly from the low-end implementation:
o Desktop ATA drives using a SATA bridge chip
o Desktop ATA controllers which are just that - desktop use
o SATA connectors aren't well latching
o SATA should have launched with multi-drives per channel

SATA *was* urgently needed - as anyone who has implemented 18" ATA
cable length limits with an 8-port 3ware card re routing & drive-bay distance.
Enterprise can come in a SATA interface - Raptor & 3ware prove it.

I hope that's clearer - there *is* a desktop v enterprise drive design difference.
Most SATA drives are *desktop drives*, Raptor is an *enterprise drive*.

Ok, perhaps Seagate are lying their ass off and we've been overpaying thro
the nose for years for Enterprise class drives which were the same as Desktop.
Perhaps, however enterprise drives seem to outlast desktop in the same task.
Therein is the marketing & engineering win for Raptor over other SATA drives.
--

Dorothy, thanks for the great information. Unfortunately, Rodney still
thinks that there is onboard termination on LVD drives. But, I do agree
that SATA is still a tad behind SCSI at this point. Like anything else, it
will get better over the years.

Rita

 

[Rita Ä Berkowitz]

Nope, they weren't the same. They were SCSI and they were offered with
a

longer warranty and they were produced in lower volume. The hype occurred
when the SCSI HD zealots oversold the advantages of SCSI and projected them
into small/modest server and highend workstation environments. There SCSI
often is NOT the best price performance solution. That became apparent over
three years ago. Some of the old wives' tales continue to hold on.

The SCSI "zealots" must be onto something. You don't see many, if any,
posts in here that their 10K or 15K Cheetah died. Seagate's 5-year warranty
is also great. How come you don't see this type of protection with ATA and
SATA drives? With the inexpensive price of U160 and U320 combined with a
5-year warranty it's a hell of a better deal going SCSI. Generally, before
you get to use this warranty the system the drive is in is obsolete. I must
ask. Why would anyone want to make such large compromises and jeopardize
their data, time, and productivity using ATA and SATA?



Rita

 

[Dorothy Bradbury]

But, I do agree that SATA is still a tad behind SCSI at this point.

Like anything else, it will get better over the years.

I do too - I am really looking forward to 2 things:
o 2.5" SAS -- compact cable + cheaper cable/termination + fast
---- Seagate Savvio - 10,000rpm albeit at a higher price
o 2.5" SATA -- may delivery it all, quicker, cheaper & sooner
---- Hitachi 7200rpm - here in ATA + Extended-use version + rugged

I will end up using 2.5"-SATA re multiple vendors & G rating.

SATA connector annoys re size & side-positioning - ATA allowed the
short-side-vertical (70mm) mounting, SATA forces long-side-vertical (100mm).

SATA-2 will really begin to get the ball rolling re daisy-chaining a la SCSI
of cheap inexpensive drives - without having to pay for 8-port $$$s cards.

 

[Rita Ä Berkowitz]

I do too - I am really looking forward to 2 things:
o 2.5" SAS -- compact cable + cheaper cable/termination + fast
---- Seagate Savvio - 10,000rpm albeit at a higher price
o 2.5" SATA -- may delivery it all, quicker, cheaper & sooner
---- Hitachi 7200rpm - here in ATA + Extended-use version + rugged

I will end up using 2.5"-SATA re multiple vendors & G rating.

The Seagate 73GB drives look nice.

SATA connector annoys re size & side-positioning - ATA allowed the
short-side-vertical (70mm) mounting, SATA forces long-side-vertical (100mm).

This is why nothing beats an SCA or FC backplane.

SATA-2 will really begin to get the ball rolling re daisy-chaining a la SCSI
of cheap inexpensive drives - without having to pay for 8-port $$$s cards.

Yeah, I never did see the logic in building a squirrel's nest of wires to do
get half the yield of a single SCSI cable. Plus, paying extra to have an
unreliable system defies all logic.



Rita

 

[Folkert Rienstra]

I do too - I am really looking forward to 2 things:
o 2.5" SAS -- compact cable + cheaper cable/termination + fast
---- Seagate Savvio - 10,000rpm albeit at a higher price
o 2.5" SATA -- may delivery it all, quicker, cheaper & sooner
---- Hitachi 7200rpm - here in ATA + Extended-use version + rugged

I will end up using 2.5"-SATA re multiple vendors & G rating.

SATA connector annoys re size & side-positioning - ATA allowed the
short-side-vertical (70mm) mounting, SATA forces long-side-vertical (100mm).

Oh? Why is that?

SATA-2 will really begin to get the ball rolling re daisy-chaining a la SCSI
of cheap inexpensive drives - without having to pay for 8-port $$$s cards.

There is no daisy chaining with SATA (nor SAS).
You will need a port multiplier or some other "concentrator" (SATA) or an "expander" (SAS).

Unless they catch on very well, they will be anything but cheap.

 

[Folkert Rienstra]

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.

So was ATA already.

o SATA plans on integrating SCSI techniques (TCQ) outside of SAS

Whatever that is supposed to mean.

---- 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

SCSI drives as well may not 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

Almost (for internal connections). There is a nodge in the SAS connector
to prevent it from being used with a SATA connector. Apparently it is
possible to connect a SATA to a SAS (internal, SATA style)connector.

---- SAS can allow dual porting to the drive for redundancy

Redundancy of what?

o SATA & SAS plan on the same host adapter even, just protocol difference
---- so enterprise with SAS HBA can mix SATA in if required

Yes, but requires extra HW, but yes, SAS allows for connecting SATA
drives through bridges with help of the Serial ATA Tunneled Protocol (STP).

 

[Dorothy Bradbury]

Folkert Reinstra wrote...

Oh? Why is that?

o Fujitsu 2.5" SATA drives have a side mounted connector
---- vertical drive & rear cable exit = drive long-side is vertical (100mm)
o All other 2.5" ATA drives have a rear mounted connector
---- vertical drive & rear cable exit = drive short-side is vertical (70mm)

The Fujitsu 2.5" SATA could be mounted short-side vertical, but that will put
the SATA cables on the top/bottom taking up space there even if rt-angle plugs.

o It could be Fujitsu are alone in side-mounting the SATA connector.
o I've not checked 2.5" drive dimensions re rear-mounting SATA data/power

I have seen 2.5" SATA RAID backplanes in a single 5.25" form-factor:
o Drives were positioned side-by-side & backplane on the rear
o That either implies rear-mounted connector for the backplane
o Or, a thin-film connector from the side to the rear for the backplane

Other 2.5" SATA RAID backplanes mount the drives pushed sideways
into the enclosure - 2.5" 100mm-length to match 3.5"-drive 100mm width.