UNH InterOperability Lab
Serial Advanced Technology Attachment
(SATA)
Use Cases
Presentation Topics
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SATA Uses in the Enterprise
SATA Uses in Personal Computing
Device Form Factors
ODD, HDD, and SSD Devices
Port Multipliers
SATA Uses in the Enterprise
• Scalability and Cost
• Cabling and
Connections
• Performance and SATA
/ SAS Compatibility
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Scalability and Cost
• SATA is highly viable for servers and
storage networks
• One SATA controller can aggregate multiple
ports
• Multiple SATA drives can be linked using
backplanes and external enclosures
Scalability and Cost
• SATA was designed to provide excellent speed and
storage at a low cost
• Cost and scalability provides potential for greater
storage capacity at a lower cost than networked or
server storage
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Cabling and Connections
• Point-to-point connectivity
• Thin and relatively small (compared to
PATA) cables allow for simple routing and
better airflow within systems
• SATA was designed to eliminate master and
slave setups as well as drive jumpers
Cabling and Connections
• Hot-swapping is
supported (drives can
be added or removed
while system is
running)
• Connectors allow for
simple external RAID
through backplanes
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SATA Cables
• Up to 1 meter in length, 7 conductors (3 grounds
and 2 pairs of data lines)
Performance and SATA/SAS
Compatibility
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First Generation SATA (1.5 Gbit/s)
Second Generation SATA (3.0 Gbit/s)
Third Generation SATA (6.0 Gbit/s)
Native Command Queuing (NCQ)
Interoperability with SAS Initiators and
Expanders
First Generation SATA (1.5
Gbit/s)
• Communication rate of 1.5 Gbit/s for data
transfer
• At the application level, only one
transaction can be handled at a given time
First Generation SATA (1.5
Gbit/s)
• Throughput capabilities similar to
PATA/133 specification
• All optical drives operate at 1.5 Gbit/s
transfer rate as well as many hard disk
drives and hosts
Second Generation SATA (3.0
Gbit/s)
• Designed to compensate for first
generation shortcomings
• Native Command Queuing (NCQ)
support added for both 1.5 and 3.0
Gbit/s devices
• Backwards compatibility with 1.5
controllers and 3.0 Gbit/s devices
Second Generation SATA (3.0
Gbit/s)
• Second Generation SATA devices can drop
to 1.5 Gbit/s transfer rate when
communicating with First Generation
devices
• 3.0 Gbit/s transfer rate supported by many
hosts and hard disk drives
Third Generation SATA (6.0
Gbit/s)
• With introduction of Solid State Disk (SSD)
drives, which operate at the 250 MB/s limit net
read speed, enhancements were required
• Isochronous data transfers in the NCQ streaming
command were added
• All DRAM cache reads operate at faster rates with
Third Generation
Third Generation SATA (6.0
Gbit/s)
• New NCQ host processing and management
• Power management improved
• Former SATA cables and connectors still
meet specification
Native Command Queuing
(NCQ)
• When drive receives multiple commands
from an application, NCQ optimizes how
the commands will be completed
• Drive must intelligently and internally
assess the destination of the logic block
addresses and then order the commands to
optimize the workload
Native Command Queuing
(NCQ)
• This is due to the fact that the mechanical
movement needed to position the read /
write head is relevant
• This improves performance and minimizes
the mechanical positioning for the drive
Native Command Queuing
(NCQ)
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• Commands are ordered in the queue to minimize
mechanical movement
Interoperability with SAS
Initiators and Expanders
• SATA protocol was designed to
interoperate with SAS
• SATA drives can be used in
many SAS enclosures
• SATA targets are designed to
connect to SAS initiators and
expanders
• However, SATA initiators cannot
connect to SAS targets and
expanders
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SATA Uses in Personal
Computing
• Better performance than and backwards
compatibility with PATA (Parallel Advanced
Technology Attachment)
• Enhanced reliability
• Flexible system integration
SATA v. PATA Performance and
Compatibility
• Simplified operation with
hot-swapping
• SATA cables have only 7
conductors (two pairs of
differential signaling lines,
one for transmission, one for
receiving and three grounds)
improving accessibility
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SATA v. PATA Performance and
Compatibility
• SATA devices can be set up to behave like
PATA devices through “legacy mode”
settings
• Devices look as if they are on a PATA
controller
• Through eSATA connectivity internal SATA
devices can connect to end systems
externally
Enhanced Reliability
• Packet integrity is verified by Cyclic
Redundancy Checking (CRC)
• CRC authenticates all data, validates that no
corruption exists
• SATA also uses CRC to communicate what
data should be read or written and to watch
drive optimization
• Available latching connectors
Flexible System Integration
• SATA is scalable, allowing for growth and
augmentations to the platform
• SATA supports all ATA and ATAPI devices
(CD, DVD, CDRW, tape devices, Zip, etc.)
• USB and IEEE1394 support for eSATA
Device Form Factors
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2.5” Side and Bottom Mounting Device
3.5” Side and Bottom Mounting Device
5.25” Optical Device
5.25” Non-optical Device
9.5 mm Slim-line Drive
12.7 mm Slim-line Drive
1.8” SATA Drive
2.5” Side and Bottom Mounting
Device
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Form Factor for SSD and HDD applications
3.5” Side and Bottom Mounting
Device
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• Form Factor for disk drives
5.25” Optical Device
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• Form Factor for CD, DVD, CDRW, DVDRW, etc. drives
9.5 mm Slim-line Drive
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• Form Factor for many laptop optical drives
12.7 mm Slim-line Drive
• Form Factor for many laptop optical drives
1.8” SATA Drive
• Form Factor for many drives designed for portable devices
and notebook computers
Types of SATA Drives
• Optical Disk Drives (ODD)
• Hard Disk Drives (HDD)
• Solid State Disk Drives (SSD)
Optical Disk Drives (ODD)
• All SATA Optical Disk Drives operate at
Generation 1 speed (1.5 Gbit/s)
• Offered in 5.25”, 9.5 mm, and 12.7 mm
form factors
• Capabilities include CD, DVD, CDRW,
DVDR, DVDRW
Hard Disk Drives (HDD)
• SATA Hard Disk Drives can operate at all
speeds: 1.5 Gbit/s, 3.0 Gbit/s, and 6.0 Gbit/s
• Operating speeds of 4200 rpm, 5400 rpm,
7200 rpm, and 10,000 rpm
• Seen in all form factors (enclosures
available for 9.5 mm and 12.7 mm are
available)
Solid State Disk Drives (SSD)
• SSD drives have many advantages over
HDD drives
• Typically composed of DRAM or NAND
memory
• No moving parts: faster startup, reading,
constant performance, silent, lower heat
production and power consumption, more
resistant to physical shock and climate
Solid State Disk Drives (SSD)
• Some disadvantages compared to HDD
drives
• Considerably higher cost, lower relative
capacities, limited write cycles, slower write
speeds
Port Multipliers
• What Port Multipliers Do
• How Port Multipliers Operate
• How Port Multipliers are Cost-effective
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What Port Multipliers Do
• From one SATA port, multiple drives or
devices can communicate
• Placed on the backplane of a SATA
enclosure
What Port Multipliers Do
• Transparent operation to the drives attached
• All SATA drives are supported
How Port Multipliers Operate
• One SATA port multiplier host connects to
many SATA drives
• Operation is similar to USB hubs but
performance is in line with an aggregated
switch
How Port Multipliers Operate
• Host bus adapter communicates with all
drives but each subsequent drive is unaware
of the multiplexing
• Drives act as if they are connected directly
to the host
How Port Multipliers Operate
• Bus to SATA Devices
• Bus to SATA PM to
Devices
• Note that the available bandwidth on the 3Gbit/s link limits
drive connectivity, maintaining efficiency and performance
How Port Multipliers are Costeffective
• Allow extended device scalability
• Up to 15 SATA devices can link to the host
with one cable
• Efficient packaging
How Port Multipliers are Costeffective
• Greater performance than Firewire / USB
external drives
• Only one host adapter is required as one
PCI slot is needed
• No performance loss
Sources
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http://www.serialata.org/technology/why_sata.asp
http://www.wisegeek.com/what-is-sata-or-serial-ata.htm
http://www.thaiinternetwork.com/backend/imagefile/0213_3.jpg
http://www.smartcomputing.com/editorial/article.asp?article=articles/archive/l0907/41l07/41l07.asp
http://www.blogcdn.com/www.engadget.com/media/2007/10/wd-scorpio-320gb.jpg
http://c1.neweggimages.com/productimage/22-136-317-03.jpg
http://computer-reviews.net/files/Toshiba%20Dual%20Layer%20DVD%20Writer.jpg
http://www.pcstats.com/articleimages/200708/LGGSAH62N_sata2.jpg
http://www.techfresh.net/wp-content/uploads/2008/09/toshiba-250gb-sata-disk.jpg
http://www.serialata.org/technology/port_multipliers.asp
http://freshisback.files.wordpress.com/2009/03/skyscraper.jpg
http://www.uriel-law.com/images/ComputerNetwork.jpg
http://www.tomsguide.com/us/intel-ss4000e-raid5-nas,review-714-4.html
http://img.tomshardware.com/us/2007/08/10/unified_serial_raid_controllers_for_pci_express/satasas.jpg
http://img.zdnet.com/techDirectory/_SATPAT.JPG
http://www.sataport.com/5-port-sata-multiplier-silicon-image2.jpg
UNH InterOperability Lab
Serial Attached SCSI (SAS)
Use Cases