Specifications for the WD Caviar® WD400BB

Model: WD400BB-75CLB0

[ download PDF spec sheet ]

Western Digital  WD400 40GB

Recommended Setup Parameters
Cylinders 1 16383 
Heads 16
Sectors/Track 63
Landing Zone 16383
WPC 16383
Jumper Setting Information Ten Pin Drive
10 and 6 Pin Jumper Settings

1 All EIDE drives 8.4 GB and larger use 16383 cylinders, 16 heads and 63 SPT due to interface restrictions.

Physical Specifications
Formatted Capacity 1 40,021 MB 
Interface 40-pin EIDE (Fast ATA-2?? EIDE is a Western Digitial proprietary specification.)
Actuator Type Rotary Voice Coil
Number of Disks 2
Data Surfaces 4
Number of Heads 4
Bytes Per Sector 512
User Sectors Per Drive 78,165,360
Servo Type Embedded
Recording Method EPR4 Rate 16/17 PRML
ECC Reed Solomon
Head Park 2 Automatic

PRML - Partial Response Maximum Likelihood
EIDE - Enhanced Integrated Drive Electronics

1 Western Digital defines a megabyte (MB) as 1,000,000 bytes and a gigabyte (GB) as 1,000,000,000 bytes
2 Turning the system power off causes the WD Caviar® to perform an automatic head park operation.

Performance Specifications
Average Seek
- Read
- Write
8.9 ms (typical) 18 ms (maximum)
10.9 ms (typical) 20 ms (maximum)
Track-to-Track Seek 2.0 ms (typical) 5 ms (maximum)
Full Stroke Seek 21 ms (typical) 28 ms (maximum)
Index Pulse Period 8.3 ms (nominal)
Average Latency 4.2 ms (nominal)
Rotational Speed 7200 RPM (nominal)
Controller Overhead 0.3 ms average
Data Transfer Rate (maximum)
- Buffer to Host





- Buffer to Disk

100 MB/s (Mode 5 Ultra ATA) [ATA/ATAPI-6]
66.6 MB/s (Mode 4 Ultra ATA)
33.3 MB/s (Mode 2 Ultra ATA)
16.6 MB/s (Mode 4 PIO)
16.6 MB/s (Mode 2 multi-word DMA)

244 Mbits/s minimum
400 Mbits/s maximum
Interleave 1:1
Buffer Size 2 MB
Error Rate - Unrecoverable <1 in 1014 bits read
Spindle Start Time
- From Power-on to Drive Ready 1
- From Power-on to Rotational Speed 2
5.5 s average, 9s maximum 
4.5 s average, 7s maximum 
Contact Start/Stop Cycles (CSS) 50,000 minimum

1 Defined as the time from power-on to the setting of the Drive Ready and Seek Complete including calibration.
2 Defined as the time from power-on to when the full spindle rotational speed is reached.

Physical Dimensions
Height English: 1.028 inches max
  Metric: 26.1 mm max
Length English: 5.787 inches max
  Metric: 147.0 mm max
Width English: 4.00 inches ±0.010 inch
  Metric: 101.6 mm ±0.25 mm
Weight English: 1.4 pounds ±0.14 pounds
  Metric: 0.62 kg ±0.062 kg

Electrical Specifications
Current Requirements and Power Dissipation
Operating Mode   RMS Current   Power, Typical 1
  12 VDC 5 VDC  
Spinup 1.8 A 560 mA 18.4 W
Read/Write/Idle 350 mA 630 mA 7.5 W
Seek 870 mA 660 mA 13.7 W
Power Management Commands
Operating Mode  RMS Current 1 Power, Typical 1
  12 VDC 5 VDC  
Idle (E1H) 340 mA 610 mA 7.1 W
Standby (E0H) 25 mA 190 mA 1.3 W
Sleep (E6H) 25 mA 80 mA 0.7 W
Input Voltage Requirements
+5.0V (±5%) and 12.0V (±10%)
Ripple
  +12 VDC +5 VDC
Maximum
Frequency
200 mV (double amplitude)
0-30 MHz
100 mV (double amplitude)
0-30 MHz
Power Connectors and Cables
Power Connector 4-pin AMP (P/N 84069-1 or equivalent)
Mating Connector Body (AMP 1-480424-0 or equivalent)
Pins (AMP 60619-4 or equivalent)
Power Cable Wire Guage 18 AWG (or heavier)

1 All values are typical (25°C, 5.0V, and 12V input) except where specified as maximum.

Note: Current measurements cut off frequency at 1 kHz.

Environmental Specifications
Shock 1
  Operating 65 G, 2 ms (read); 20 G, 2 ms (write)
  Non-operating 250 G, 2 ms
Vibration
  Operating Linear: 5-500 Hz, 0.25 G (0 to peak)
Random: 10-300 Hz, 0.004 g2/Hz
  Non-operating 5-20 Hz, 0.195 inches (double amplitude)
20-500 Hz, 4.0 G (0 to peak)
  Sweep Rate 0.5 octave/minute minimum
Drive Generated Vibration
  Operating 0.4 gm-mm typical with the drive in an unconstrained condition
Rotational Shock Non-Operating
  Amplitude 20 K rad/sec2
  Duration 2 ms
Operating Temperature and Humidity
  Temperature 5°C to 55°C (41°F to 131°F)
5°C to 65°C (case temp)
  Humidity 5-85% RH non-condensing
33°C (maximum wet bulb)
  Thermal Gradient 20°C/hour (maximum)
  Humidity Gradient 20%/hour (maximum)
Non-Operating Temperature and Humidity
  Temperature -40°C to 60°C (-40°F to 140°F)
  Humidity 5-95% RH non-condensing
33°C (maximum wet bulb)
  Thermal Gradient 30°C/hour (maximum)
  Humidity Gradient 20%/hour (maximum)
Altitude
  Operating -1000 feet to 10,000 feet (-305M to 3,050M)
  Non-Operating -1000 feet to 40,000 feet (-305M to 12,200M)
Acoustics
  Idle Mode 2 35 dBA average 
  Seek Mode 0 3 37 dBA average 
  Seek Mode 3 3 34 dBA average 
Reliability Specifications
  AFR <0.8%
  MTBF 500,000 Power On Hours
  Component Design Life 5 years
Warranty Period Warranty Length

1 Half sine wave, measured without shock isolation and without non-recoverable errors.
2 No audible pure tones.
3 Random seek at a rate of 26 seeks per second.

this page posted March 2005
lyberty.com