IBM System/370 145 Manual page 17

• Potential increases in channel throughput via use of block
multiplexing and rotational position sensing to improve effective
data transfer rates
• A significantly higher attainable aggregate channel data rate than
the Model 40 to balance' the higher performance capabilities of the
Model 145 CPU
Faster I/O Devices and
Increasec~
Direct Access Storage Capacity
The Model 145 supports a fast:er magnetic tape unit than do Models 30
and 40--specifically, the 3420 ltlodel 7 with a data rate of 320 KB.
A Model 145 I/O configuration can also include significantly more and
faster direct access storage.
l~or
example, the Model 145 is not limited
to having 2314 facilities on onl.y one channel, as are Models 30 and 40.
In addition, the 3330-series and 2305 Model 2 provide considerably more
capacity and faster data access than 2314 facilities or 2303 Drum
Storage because of higher data t~ransfer rates, faster rotation, and new
features. IJ.'hese direct access devices also offer higher availability
through use of new hardware-oIlly and program-assisted error correction
features.
The 3330-series provides largre capacity and fast access for a lower
cost per bit. It is
a
growth de!vice that offers improved price
performance for the 2314 facilit~y and the 2321 Data Cell Drive. The
3330-series is designed to be us:ed in every area in which direct access
storage is needed, for example:
• As a system residence device~ and for program library storage
• In teleprocessing applications for message queuing and for residence
of online applications data
• In online, data base applications, such as management information
systems
• In time sharing (or interact,ive) environments as swap devices and
for online work storage (foz' program and data residence)
• As high-speed work storage f'or sorting, assembling, and link editing
• For residence of data indexes, such as for ISAM data sets
• As external page storage in a virtual storage environment
The 2305 Model 2 facility off'ers significantly faster access than,
and almost three times the capacity of, the 2303 drum. In large
Model 145 OS installations, the 2305 facility will be of benefit:
• As the pr;imary system residence device
• In time sharing environments as a swap device and for program and
data residence
• As high-speed work storage and for residence of data indexes
• As external page storage in a virtual storage environment
A, Guide to the IBM System/370 Model 145 7