Quantum sdlt 220 Guía Del Usuario
CHAPTER 3: Drive Specifications
SDLT 220 and SDLT 320 Product Manual
3-4
March 2004
81-85002-01
3.1.6 Maximum Data Transfer Rate
The maximum sustained (and burst) data transfer rates for SDLT drives are shown in
.
N
OTE
: Cable lengths and cable type can limit attainable transfer
rate; for details, refer to a separate document,
SDLT 220 and SDLT 320 Design and Integration Guide,
81-81148-01.
SDLT 220 and SDLT 320 Design and Integration Guide,
81-81148-01.
3.1.7 Head Life and MTBF
Mean time between failures (MTBF) for the overall tape system is projected to be
250,000 hours, not including the heads. Head life is a minimum of 30,000 tape
motion hours and an average of 50,000 tape motion hours.
250,000 hours, not including the heads. Head life is a minimum of 30,000 tape
motion hours and an average of 50,000 tape motion hours.
Table 3-4.
Maximum Data Transfer Rates
SDLT 220
Sustained
SDLT 220
Burst
Max*
Max*
SDLT 320
Sustained
SDLT 320
Burst
Max*
Max*
Config-
uration
Native
Com-
pressed‡
pressed‡
Native
Com-
pressed‡
pressed‡
HVD
(Ultra 1
SCSI)
(Ultra 1
SCSI)
Narrow
11 MB/sec
20 MB/sec
20 MB/sec
16 MB/sec
20 MB/sec
20 MB/sec
Wide
11 MB/sec
22 MB/sec
40 MB/sec
16 MB/sec
32 MB/sec
40 MB/sec
LVD
(Ultra 2
SCSI)
(Ultra 2
SCSI)
Narrow
11 MB/sec
22 MB/sec
40 MB/sec
16 MB/sec
32 MB/sec
40 MB/sec
Wide
11 MB/sec
22 MB/sec
80 MB/sec
16 MB/sec
32 MB/sec
80 MB/sec
* Burst speeds are limited by the SCSI bus itself, not the design of SDLT 220/320 or Super DLTtape media.
‡ The compression rates shown assume an industry standard 2:1 compression ratio. Actual compression ratios
achieved depend on the redundancy of data files being recorded. For non-compressible (expanding) data, this
results in a reduction in capacity and transfer rate for the data. Fully random data is the worst case for
compressibility.
results in a reduction in capacity and transfer rate for the data. Fully random data is the worst case for
compressibility.