Gateway M-6750 250GB(5400RPM) Sata Hard Drive - WD2500BEVSWD2500BEVS-22USTO - WD2500BEVSFeature Description Manufacturer Western Digital Model WD2500BEVS-22UST0 Size 250 GB Interface SATA 1.5 Gb/s Actuator type Rotary voice coil Number of disks 2 Data surfaces 4 Number of heads 4 Bytes per sector 512 User sectors per drive 488,397,168 Servo type Embedded Recording method Partial DC Target ECC Reed-Solomon Average seek Read 12 ms (average) Average seek Write 13 ms (average) Track-to-track seek 2.0 ms (average) Full stroke seek 21 ms (average) Index pulse period 11.1 ms (nominal) Average latency (msec) 5.5 Rotational speed 5,400 RPM Data transfer rate Buffer to host: 1.5 Gb/s maximum Buffer to disk: 850 Mbits/s maximum Interleave 1:1 Buffer size 8 MB Error rate (non-recoverable) <1 in 1014 bits read Spindle start time Power-on to drive ready: 4.0s averagePower-on to rotational speed: 3 2.0s average Spindle stop time 5.1s average Load/Unload cycle 600,000 Power requirement 5 V Temperature Operating: 0 to 60 C (32 to 140 F)Non-operating: -40 to 65 C (-40 to 149 F) Humidity Operating: 8 to 90 RH non-condensingNon-operating: 5 to 95 RH non-condensing Shock Operating: 2 msec (Gs): 300GNon-operating: 1 msec (Gs): 900G Height 9.5 millimeters ( .374-inches) Width 69.85 mm (2.75-inches) Depth 100 mm (3.945-inches) Weight 99 grams (0.22 pounds)