Instructions per second

Instructions per second (IPS) is a measure of a computer's processor speed. Many reported IPS values have represented "peak" execution rates on artificial instruction sequences with few branches, whereas realistic workloads typically lead to significantly lower IPS values. The performance of the memory hierarchy also greatly affects processor performance, an issue barely considered in MIPS calculations. Because of these problems, researchers created standardized tests such as SPECint to attempt to measure the real effective performance in commonly used applications, and raw IPS has fallen into disuse.

The term is commonly used in association with a numeric value such as thousand instructions per second (kIPS), million instructions per second (MIPS), Giga instructions per second (GIPS), or Million Operations per Second (MOPS).

Timeline of instructions per second
This is a timeline listing the instructions per second, in terms of MIPS (Million Instructions Per Second), for various microprocessor-based arcade systems, game consoless and personal computers.

The table also lists the bits of the CPU (central processing unit) and GPU (graphics processing unit), as well as the system's floating-point performance in terms of MFLOPS (Million Floating-point Operations Per Second).

Note that the MIPS, MFLOPS and Bits are not always necessarily indicative of graphical prowess, especially when it came to 2D graphics, which were more dependent on the sprite and colour capabilities of a GPU chipset (see Hardware sprites, Evolution of arcade video game hardware, and List of home computers by video hardware).