UNH InterOperability Lab

Serial Advanced Technology Attachment (SATA)

Use Cases

Presentation Topics

• 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

• 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)

• Commands are ordered in the queue to minimize mechanical movement

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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

• 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

• Form Factor for SSD and HDD applications

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3.5” Side and Bottom Mounting Device

• Form Factor for disk drives

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5.25” Optical Device

• Form Factor for CD, DVD, CDRW, DVDRW, etc. drives

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9.5 mm Slim-line Drive

• Form Factor for many laptop optical drives

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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

• Note that the available bandwidth on the 3Gbit/s link limits drive connectivity, maintaining efficiency and performance

• Bus to SATA Devices

• Bus to SATA PM to Devices

How Port Multipliers are Cost-effective

• Allow extended device scalability

• Up to 15 SATA devices can link to the host with one cable

• Efficient packaging

How Port Multipliers are Cost-effective

• Greater performance than Firewire / USB external drives

• Only one host adapter is required as one PCI slot is needed

• No performance loss

Sources• 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/sata-

sas.jpg• http://img.zdnet.com/techDirectory/_SATPAT.JPG• http://www.sataport.com/5-port-sata-multiplier-silicon-image2.jpg

UNH InterOperability Lab

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