Capacity And Timing Characteristics Of The 3330 And 2314 Facilities And The 2321 Data Cell Drive - IBM System/370 Manual

If a 2321 is replaced by a 3330, six full track blocks of data
from the 2321 (2000 bytes/2321 track) can be placed on each 3330 track
if full track blocking is used, for a total of 92,112,000 bytes per
3336 pack (12,000 bytes x 7676 tracks per 3336). Thus, slightly over
four 3336 packs provide the capacity equivalent of ten data cells,
or a full 2321 drive, if full tracks are used. A full ten data cells,
blocked full track, also can be contained in slightly more than four
3336 packs if half-track blocking is used on the 3336.
Table 20.10.1. capacity and timing characteristics of the 3330 and
2314 facilities and the 2321 Data Cell Drive
Characteristics 3330 2314 2321
Capacity in bytes truncated
to the nearest thousand
(full track records)
Pack or cell
100,018,000
29,,176,000
39,200,000
Facility or Data Cell Drive
2 drives/cells
200,036,000 58,352,000 78,400,000
4 drives/cells 400,073,000 116,704,,000 156,800,000
6 drives/cells 600,109,000 175,056,000 235,200,000
8 drives/cells 800,146,000
233,408,000 313,600,000
10 cells
- -
392,000,000
Access time in ms
Maximum 55 130 600 (for strip
select and
load)
Average
30 60 175 (minimum
for strip select
and load)
Average cylinder to
10 25
95 (on a strip)
cylinder
Rotation time in ms 16.7 25 50 (strip on
drum)
Rotation speed (rpm)
3600 2400 1200
Data transfer rate
(KB)
806 312 55
Table 20.10.2. 3336 and 2316 Disk Pack characteristics
Characteristics
3336 2316
Number of disks per pack
12 13
Number of recording disks
10 11
Number of recording surfaces
I
(recorded tracks per pack)
Disk thickness in inches
I
DiSk diameter in inches
Disk pack weight in pounds
19
.075
14
20
100
20
.050
14
15
I
Disk pack maximum capacity in
millions of bytes
Full track capacity in bytes
Cylinders per pack
Tracks per cylinder
Tracks per pack
13,030
404 plus 7
alternates
19
7676
29.1
7294
200 plus 3
alternates
20
4000
Self-formatting records are written on 3336 packs in the same manner
as they are on 2316 packs. However, each physical area written (count,
key, and data) has a field of error correction code appended to it
for the purpose of data validity checking by the control unit instead
of the cyclic check area used on the 2314.
38