Skip to main content

System/370 CPU characteristics*
Model Data Flow Width (bytes) Cycle Time (nanoseconds)
115 1 480
115-2 2 480
125 2 480
125-2 2 320-480 (1)
135 2 275-1485 (1)
135-3 2 275-1485 (1)
138 2 275-1430 (1)
145 4 (2) 203-315 (1)
145-3 4 (2) 180-270 (1)
148 4 (2) 180-270 (1)
155 4 115
155-II 4 115
158 4 115
158-3 4 115
165 8 80
165-II 8 80
168 8 80
168-3 8 80
195 8 54

(1)  Variable, depending on the type of operation performed.
(2) An 8-byte-wide path is used for instruction fetch.

* Source: A. Pedegs, "System/360 And Beyond," IBM Journal Of Research And Development, Vol. 25, No. 5, September 1981, Table 1, pp. 388-389.


System/370 control storage characteristics*
Model Size (K Words) Type Cycle Time (nanoseconds)
115 20-28 RW 480
115-2 12-20 (1) RW 480
125 12-20 RW 480
125-2 16-24 RW 320
135 12-24 RW 275
135-3 64 RW 275
138 64 RW 275
145 8-16 (2) RW 203
145-3 32 RW 180
148 32 RW 180
155 6 RO 115
155-II 8 RO 115
158 8 RW 115
158-3 8 RW 115
165 2 RO 80
165-II 4 RO 80
  1 RW 80
168 2-3.5 RO 80
  0.5-1 RW 80
168-3 2-3.5 RO 80
  1-2 RW 80
195 none    

K = 1024
RO = Read-only
RW = Read-write (writable)

(1)  The 115-2 contains a separate I/O processing unit for some functions that were executed on the CPU in a 115; hence a smaller CPU control-storage capacity.
(2)  Part of this capacity is physically in processor storage and thus has to be subtracted from the available processor-storage capacity.

* Source: A. Pedegs, "System/360 And Beyond," IBM Journal Of Research And Development, Vol. 25, No. 5, September 1981, Table 1, pp. 388-389.


System/370 processor storage characteristics*
Model Size (K bytes) Bus Width (bytes) Cycle Time (nanoseconds)
115 64-192 2 480
115-2 64-384 2 480
125 96-256 2 480
125-2 96-512 2 480
135 96-512 2 990 (1) R
      935 (1) W
135-3 256-512 2 990 (1) R
      935 (1) W
138 512-1024 2 935 (1)
145 160-2048 8 540 R
      608 W
145-3 192-1984 8 405 R
      540 W
148 1024-2048 8 405 R
      540 W
155 256-2048 8 2070 (2)
155-II 256-2048 8 2070 (2)
158 512-6144 8 1035 R
      920 W
158-3 512-6144 8 920
165 512-3072 8 x 4 2000 (2)
165-II 512-3072 8 x 4 2000 (2)
168 1024-8192 8 x 4 320
168-3 1024-8192 8 x 4 320
195 1024-4096 8 x 16 756

K = 1024
R = Access for reading.
W = Access for writing.

(1)  Four bytes can be accessed and transferred in this time.
(2)  Uses magnetic-core technology.

* Source: A. Pedegs, "System/360 And Beyond," IBM Journal Of Research And Development, Vol. 25, No. 5, September 1981, Table 1, pp. 388-389.

2-2 of 2 pages | Previous