There are many different kinds of CPU which are used in a computer.These differences in terms of hardware and architecture go unnoticed by most people, but they make all the difference when it comes to how a computer works at its core! The majority of them accomplish basic CPU operations such as reading and writing data, simple arithmetic, and address shifting. They call these operations for each CPU cycle.
It’s possible for two identical pieces of hardware to differ in terms of processor architecture and bus sizes. There are two major types of CPUs used in computers today: Scalar and Superscalar.
The scalar processor is a more “traditional” CPU, which operates on one task at a time. Therefore, the scalar processor needs the full number of cycles to process one operation before it can move on to the next.
The superscalar CPU processes multiple operations at a time. Although the superscalar CPU needs more time to process each operation than a scalar processor, it can do multiple operations in the same amount of time.
Scalar vs. Superscalar Processors
The difference between scalar and superscalar processors is that the former process one instruction at a time, whereas the latter can execute several instructions simultaneously. The terms “scalar” or “superscalar” are not to be confused with “single-core/multi-core.” Scalars are single-core processors, while superscalars may either be single- or multi-cores.
The key point is that scalars cannot perform more than one operation (i.e., carry out more than one instruction) per clock cycle, but superscalars can–up to two instructions in some cases. This means that if you have a CPU with three cores on it–one being an old scalar processor–and you run an application that utilizes all three cores, the old third core will be no more than half as fast as if it were completely superscalar.
The main thing to remember is that certain instruction sets are suited better to certain optimizations. Superscalars can execute basic operations such as add and load on separate registers simultaneously, whereas a scalar processor would have to complete one operation before moving on to the next.
For example, a scalar processor may be able to run multiple threads, but they will all share the same core and therefore only run as fast as the slowest thread. Superscalars can provide much higher performance because each thread gets its own core/execution unit.