SATA
http://www.sata-io.org/technology/why_sata.asp
Data transfer rate - Direct SATA - Internally connected
I 1.5 gigabits per second (150 MB/s)
II 3.0 gigabits per second (300 MB/s)
III 6.0 gigabits per second (600 MB/s)
eSATA - External SATA
http://www.sata-io.org/technology/esata.asp
http://www.sata-io.org/images/eSATA-logo-1.5Gbs_Color.gif
Comparison of Interface speeds and data transfer rates for external disk drive interfaces
USB2 1394 Serial
Raw Interface Speed 480Mbps 400Mbps 1500Mbps
Benchmark Comparison 64K read 31.6 MB/sec 34.8MB/sec 42.4MB/sec
Benchmark comparison 64K write 26.5 MB/sec 26.7MB/sec 56.2MB/sec
Burst Transfer Rate 33.5MB/sec 36.2MB/sec 111.3MB/sec
Superior Link Utilization: Today, an average hard drive operating off its rotating media
(not its cache) might sustain 80 MB/s, a figure much lower than the theoretical maximum
throughput of ~600 MB/s offered by SATA 6Gb/s. With support for up to 15
drives, SATA’s unique port multiplier capabilities enable users to aggregate multiple
drives behind a single SATA port in order to fully utilize host link capacity. In this way,
data across several drives appears as a single logical bank of data. Port multipliers help
to relieve storage bottlenecks, especially in applications such as entry-level servers and
high-bandwidth applications like video post-production.
SAS
http://www.scsita.org/aboutscsi/sas/SAS_roadmap.html
Ultra 320 SCSI
SAS I 3 Gbps
SAS II 6 Gbps ( back ward compatible) - at present
SAS III 12Gbps
1. What is the definition of Serial Attached SCSI?
Serial Attached SCSI (SAS) is the logical evolution of SCSI that satisfies the enterprise data center requirement for scalability, performance, reliability and manageability, while leveraging a common electrical and physical interface with Serial ATA (SATA). This compatibility provides users with unprecedented choices for server and storage subsystem deployment.
2. Why was Serial Attached SCSI developed?
was developed to address I/O and direct attach storage requirements that traditional parallel SCSI cannot meet. It provides universal interconnect with SATA, while offering logical SCSI compatibility along with SCSI reliability, performance and manageability.
http://www.scsita.org/aboutscsi/sas/STA_6G_SAS.pdf
Results
SCSI System:Access Time: 7.6 ms
Max Read: 141.6 MB/s Min Read: 54.5 MB/s Average Read: 119.6 MB/s
SAS System:
Access Time: 5.8 ms
Max Read: 196.0 MB/s Min Read: 117.9 MB/s Average Read: 172.1 MB
SATA WD Caviar Black 1TB Drive:
Access Time: 12.5 ms
Max Read: 108.6 MB/s Min Read: 52.9 MB/s Average Read: 85.1 MB/s
Disk enclosures/Storage
MD3000/MD3000i - DELL
MD3000i 48MB/s - throughput
http://tools.ietf.org/html/rfc3720
still to come.... wait for this.
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