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

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

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

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

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

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

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

3.5” Side and Bottom Mounting Device Form Factor for disk drives

5.25” Optical Device Form Factor for CD, DVD, CDRW, DVDRW, etc. drives

9.5 mm Slim-line Drive 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

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 sas.jpghttp://img.tomshardware.com/us/2007/08/10/unified_serial_raid_controllers_for_pci_express/sata- sas.jpg

UNH InterOperability Lab Serial Attached SCSI (SAS) Use Cases