Instructions per second

Memory hierarchy also greatly affects processor performance, an issue barely considered in IPS calculations.

Because of these problems, synthetic benchmarks such as Dhrystone are now generally used to estimate computer performance in commonly used applications, and raw IPS has fallen into disuse.

IPS can be calculated using this equation:[1] However, the instructions/cycle measurement depends on the instruction sequence, the data and external factors.

Other ratings, such as the ADP mix which does not include floating point operations, were produced for commercial applications.

This was chosen because the 11/780 was roughly equivalent in performance to an IBM System/370 model 158–3, which was commonly accepted in the computing industry as running at 1 MIPS.

The Whetstone Report has a table showing MWIPS speeds of PCs via early interpreters and compilers up to modern languages.