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File 8360-01
Form A22-6825-1




Systems Reference Library




System/360 Instruction Timing Information

This bulletin contains instruction timing in-
formation for all models of the 8ystem/360.
For a full description of each instruction,
refer to IBM 8ystem/360 Principles of
Operation, Form A22-6821.
MAJOR REVISION (May 1964)
This publication, Form A22-6825-1, obsoletes
Form A22-6825-0, N22-0133, and N22-0135.




Copies of this and other IBM publications can be obtained through IBM Branch Offices.
Address comments concerning the contents of this publication to:
IBM Corporation, Customer Manuals, Dept. 898, PO Box 390, Poughkeepsie, N.Y. 12602
SYSTEM/360 INSTRUCTION TIMING INFORMATION


The instruction time tables presented in this bulletin 2. In all storage operations, positive and negative
provide average instruction times, in microseconds, operands are equally probable.
f~r all models of the IBM System/360. All times for 3. Each bit location has equal probability for the
instructions that reference storage include the time binary values 0 or 1, and each bit location is
required to perform single indexing by one general independent of other bit locations. Decimal data
register as referenced in the instruction (i. e., B 1= 0) . may contain digit values 0 to 9 in eaoh digit
For those instructions in which indexing may be per- position with equal probability.
formed two times (i. e. , all RX format instructions), 4. Variable field length instructions may start on
the time required for the second indexing must be even or odd halfwords with equal probability.
added to the basic time given in the table, as follows: 5. Interruptions or masked-off program exceptions
are not reflected in these timings.
MODEL ADDITIONAL TIME (in microseconds)
TIMING ASSUMPTIONS
30 6.0
40 1.25
SO 0.5 The following assumptions were used in the devel-
60 0.125 opment of these instruction time tables.
62 0.125
70 0.0 1. For decimal-add and decimal-subtract instruc-
tions, the first operand (i. e. , the destination
The instructions that may be indexed a second field) is assumed to be greater than, or equal
time are highlighted by an asterisk in the table. to, the length of the second operand (i. e. , the
source field).
TIMING CONDITIONS 2. For decimal-add and decimal-subtract instruc-
tions, recomplementation time is not included
The following conditions were used in the develop- in the times given.
ment of these instruction time tables. 3. In the EDIT AND MARK (EDMK) instruction,
1. All instruction timings pertain only to storage an address is stored once. That is, this instruc-
references to main storage as follows: tion is used with a single field, or a line with
only one numeric field rather than a complete
print line.
MODEL SPEED (in microseconds) WIDTH (in bytes) 4. In the TRANSLATE AND TEST (TRT) instruc-
tion, it is assumed that a non-zero byte from
30 2.0 1
40 2.5 ' 2
the Translate and Test table is found.
SO 2.0 4 5. The instruction times for the floating-point in-
60 2.0* 8 structions depend -upon the number of hexidecimal
62 1.0 8 digits that are pre shifted and postshifted, as well
70 1.0* 8 as the number of times recomplementation of a
* Interleaved. Provides reduced access time for consecutively result occurs. The times given in the instruction
addressed references by overlapping storage cycles of odd time tables for floating-point instructions are
and even addresses. a weighted average of these variables.




3
SYSTEM / 360

MODEL
30 40 50 60 62 70
INSTRUCTION FORMAT MNEMONIC Time Time Time Time Time
Time
Blo Blo Blo Blo BIO s/o

Add RR AR 29. 7.5 3.25 1.0 .84 .4

Add * RX A 39. 11.88 4.0 2.81 1.87 1.05

Add Decimal 55 M See Table AP

Add Halfword * RX AH 37. 10.94 5.5 3.44 2.37 1.12

Add Logical RR ALR 30. 7.5 3.25 1.0 .84 .4

Add logical * RX AL 40. 11.88 4.0 2.81 1.87 1.05

Add Normalized (long) RR ADR 105. 22.53 7.84 2.35 2.19 .85

Add Normalized (Long) * RX AD 115. 27.66 9.69 4.05 3.22 1. 13

Add Normalized (Short) RR AER 65. 14.3 6.13 2.33 2.17 .85

Add Normalized (Short) * RX AE 75. 18.66 6.88 4.03 3.20 1.13

Add Unnormalized (Long) RR AWR 88. 20.86 7.15 2.29 2.13 .90

Add Unnormalized (Long) * RX AW 98. 25.99 9.00 3.99 3.16 1.15

Add Unnormalized (Short) RR AUR 56. 13.59 5.38 2.26 2.10 .9
-_..
Add Unnormalized (Short) -k RX AU 66. 17.95 6.13 3.96 3.13 1. 15

AND RR NR 30. 7.5 5.0 1.75 1.59 .6

AND * RX N 40. 11.88 5.75 3.44 2.62 1.08

AND 51 NI 20. 9.38 6.5 4.18 2.43 2.2

AND SS NC See Table NC

Branch and Link RR BALR B 24. B 8.75 B 4.25 2.25 1.53 1.0
NB 19. L 6.88 NB 3.0

Branch and Li nk * RX BAL 35. 11.88 4.5 2.40 1.53 1.0

Branch on Condition RR BCR B 14. B 5.01 B 3.75 B 2.25 B 1.53 1.0
NB 9. NB 4.39 NB 2.75 NB 1.00 NB .84

Branch on Condition