16
Mass storage
The hard disk drive can be removed by the user for easy upgrades. The hard drive
is located on the bottom case and with the removal of one screw the hard drive can
be replaced.
Hard drive manufacturer: IBM
and Toshiba (subject to change without notice).
2.5" Hard Drive 540MB 810 MB 810 MB 1,215MB
AT Interface RLL ATA2 Interface ATA2 Interface ATA2 Interface
HDD (Toshiba)
Note: VL models
shipping 11/95
will have the
540MB option
HDD (Toshiba) HDD (IBM)
Note: Current plan
is to dual source
the 810MB hard
drive, currently the
Toshiba 810 is the
major supplier
HDD (IBM)
Note: Currently
the 1.2GB drive is
sole sourced from
IBM.
Average seek
(read)
12 ms 12 ms 12 ms 12 ms
Track to track seek 3 ms 3 ms 4 ms 4 ms
Full Track NA 25 ms 23 ms 23 ms
Average latency 7.5 ms 7.1 ms 6.1 ms 6.1 ms
Rotational speed 4000 rev/m 4200 rev/m 4900 rev/m 4900 rev/m
Data transfer rate:
Media Transfer
rate
18.9-31.6
Mbits/sec
43.75 Mbits/sec
(max.)
36.3 (inner), 57.0
(Outer) Mbits/sec
36.3 (inner), 57.0
(Outer) Mbits/sec
Buffer to host 6 Mbytes/sec 11.1Mbytes/sec 11.1Mbytes/sec 11.1Mbytes/sec
Buffer size 128 Kbytes static
RAM
128Kbytes static
RAM
64KB (read and
write segmented
buffer)
64KB (read and
write segmented
buffer)
Spindle start time 5 sec (typical) 5 sec (typical) NA NA
Reliability:
MTBF: Power-on
Hours
300,000 hours 300,000 hours 300,000 hours 300,000 hours
Unrecoverable
errors
1 in 1013 (bits) 1 in 1013 (bits) 1/1.0E 13 bits
transfer
1/1.0E 13 bits
transfer
Configuration:
2.5" Hard Drive 540MB 810 MB 810 MB 1,215MB
