WD Raptor 74GB

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WD Raptor 74GB

• The Evolution of Enterprise SATA

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WD Raptor 74GB

• Higher capacity
• Now 74GB
• Faster performance
• Raw data rate improvements
• Addition of command queuing
• Even better rotational vibration rejection
• Features Rotary Accelerometer Feed Forward (RAFF)
• All at a significantly lower price than SCSI

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WD Raptor Enterprise Serial ATA

• Matches reliability and performance attributes of
  SCSI
• Enterprise class mechanical platform
• 1.2Mhrs MTBF, 5 year warranty
• 10,000 rpm, 4.5ms seek
• 74GB, 8MB buffer
• SATA interface
• Thermal sensor
• Command queuing for performance
• RAFF for rotational vibration rejection
• Support for drive activity LED through pin 11

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WD Raptor 74GB Benchmark Improvements
Chart shows preliminary benchmark percentage
improvements over WD Raptor 36GB
WD Raptor 74GB is faster than current 36GB
version
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Enterprise SATA Enablers

• Motherboards, HBAs, backplanes, enclosures all
  shipping in volume
• Price point combined with capacity point of 74GB
  is an even more attractive proposition for system
  builders
• System builder guide at www.esata.com

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SAS-like Design Flexibility with SATA

• The promise of Serial Attached SCSI (SAS)
• Ability to attach high performance SAS and low
  cost, high capacity SATA on the same backplane
• Allows system integrators to be flexible in
  meeting customer application needs with one
  design
• No need to wait for SAS!
• The same flexibility is available now with SATA
• Attach 10,000rpm WD Raptor drives for high
  performance
• Attach 7200rpm WD Caviar drives for high
  capacity, low /GB

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Rotational Vibration

• What is Rotational Vibration?
• Effect of making a drive vibrate about its center
  of mass
• Induced by other drives spinning and seeking in
  the same rack
• Can also be externally induced by the rack or
  case
• What is the effect?
• Loss of performance
• Head is prevented from settling on track or is
  shaken off track
• Inability to read or write on track due to
  external forces
• Causes retries and consequent loss of performance
• Ultimately drive may not be able to respond at
  all

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Rotary Accelerometer Feed Forward (RAFF)

• Detect Rotary Vibration using accelerometers
• Feed information forward to the servo system
• Apply correction to head positioning
• Keep the head on track despite vibration
• Maintains performance despite RV
• Faster recovery, reduce missed revs
• First generation WD Raptor was competitive to
  SCSI with regard to RV management
• This generation is 33 better

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Summary

• Higher capacity
• Popular 74GB capacity point covers bulk of SCSI
  volume
• Faster performance
• Higher data rate and faster seek times
• Addition of command queuing
• WD Raptor leading the industry in Enterprise SATA
• Complements WD Caviar Special Edition SATA drives
• Added enterprise features RAFF and command
  queuing