ATTO Technology Diamond Storage Array S-Class - Manual (Page 98)

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ATTO Technology Inc.
Appendix A ATA Disk Technology
ATA is the dominant disk drive technology today and will be for the foreseeable future. It offers all the
cost advantages of a mass produced, consumer-driven technology which is rapidly being driven
forward. Today ATA also offers all the performance and reliability features needed to create high
performance ATA-based disk storage arrays.
We view ATA as the perfect disk drive technology for “in-the-box” disk storage array solutions.
Aggregated Data Interface Technology (ADXT
™) with its built-in Virtual Device Manager (VDM), Data Routing
Fabric (DRF) and ATA Interface Engines (AIE) smoothly and efficiently organizes Fibre Channel data streams
for storage or retrieval on ATA disk drives. ADXT provides end users with the power and sophisticated data
control needed to take moderately priced ATA disk drives combine them in a disk storage array and power them
to the performance levels of SCSI or Fibre Channel disk arrays
Unlike other storage arrays which use expensive SCSI or Fibre Channel disk drives to achieve performance, the
Diamond Series uses lower cost ATA disk drives combined with an intelligent midplane to create a storage array
with exceptional price and performance characteristics.
ATA disk drives are used in the enormous PC marketplace and an estimated 85% of all disk drives sold today
contain an ATA interface. Shipments of ATA drives are expected to grow rapidly over the next five years with
increasing consumer and business demand. In general, ATA disk drives are the “driver” of all disk storage
technology as the costs, volumes and demands of the PC marketplace are the primary focus of the world’s largest
disk drive manufacturers.
ATA disk drives today offer capacities comparable to SCSI and FC disk drives – although at a tremendously lower
cost. Advances in platter and head technology will push drive capacity along a very steep curve in the next five
years. Interface advances are also planned for ATA drives with an Ultra100 ATA interface expected in 2001. This
interface will provide low cost, simple and reliable communication just as ATA66 does, but at a much higher data
rate.
Exhibit A-1 summarizes ATA and other disk interface standards. It clearly indicates that ATA drive technology
offers characteristics that ideally suit it for “in the box” usage in high capacity, high performance disk arrays.
Exhibit A-1 Disk features and standards
Feature IDE ATA SCSI Fibre Channel
Connectivity
Max Devices
Cable Length
2
46 cm
2
46 cm
16
25 m
126...millions
10 km
Performance
Bandwidth
Bandwidth/drive
Multi-threaded I/O
16 MB/sec.
8 MB/sec.
No
66 MB/sec.
33 MB/sec.
Yes
160 MB/sec.
10 MB/sec.
Yes
200 MB/sec.
1.6 MB/sec.
Yes
Max Initiators 1 1 <16 125...millions
Topology Bussed Bussed Bussed Loop/Fabric
Error Detection None Yes Yes Yes
Protocol “weight” very light light medium to heavy heavy
Cost
Interface
Drives
n/a
n/a lowest
lowest medium to high
medium to high highest
medium to high
Manageability none low to medium medium medium+