Instruction execution time (CPU) over time
Time to execute one named instruction. The method separates addition from multiplication, but native operations can still differ in word width, addressing, and precision. These timings do not support cross-machine speed multipliers.
- Device scope
- cpu
- Method
- Addition instruction
- Plotted in
- second
Chart
3 figures from 3 machines, spanning 1965 to 1966. The lowest instruction execution time here is 3.2 µs (DEC PDP-8, 1965) and the highest is 82 µs (Saturn Launch Vehicle Digital Computer, 1966). The two are not divided into a multiple: these records do not support a like-for-like ratio. The figures are plotted in s. Points use the release date of the machine the figure belongs to. The table below lists absent figures with their recorded reasons.
Data
| Machine | Released | Figure | Confidence | Sources |
|---|---|---|---|---|
| DEC PDP-8 DEC PDP-8 processor | 1965 | 3.2 µs Direct-address TAD Y instruction in DEC Table 1. | Vendor-rated | |
| Apollo Guidance Computer (Block II) Apollo Guidance Computer Block II processor | 1966 | 23.4 µs Single-precision addition: two 11.7 µs memory cycles. | Vendor-rated | |
| Saturn Launch Vehicle Digital Computer Saturn Launch Vehicle Digital Computer | 1966 | 82 µs Add-subtract, 26 bit accuracy. Add-subtract and multiply-divide run simultaneously. | Vendor-rated |
Why this chart holds one group only
Every point on a chart is implicitly compared with every other point on it. This chart uses one comparability group: one metric, one device scope, one method . There is no chart of all clock frequencies over time because they are not one quantity.
These are timings for each machine's native operation. Word width, addressing, and arithmetic can differ. Read the conditions beside each figure; the chart does not claim a common workload or a speed multiplier.
Points use the release date of the machine a figure belongs to, including figures recorded against a part. A release date applies only to a machine that shipped. What this metric measures.