As computers have evolved, CPUs have not just become faster — they have also gained more cores. In IB Computer Science, students are expected to understand the difference between single-core and multi-core processors and how this affects performance, multitasking, and program execution.
Many students assume that more cores automatically means better performance. In reality, performance depends on how software uses those cores.
What Is a CPU Core?
A core is an individual processing unit within a CPU.
Each core can:
- Fetch instructions
- Decode instructions
- Execute instructions
A single-core processor has one core that handles all tasks. A multi-core processor has two or more cores, each capable of working independently.
Single-Core Processors
In a single-core processor:
- All instructions are processed by one core
- Tasks are executed sequentially
- Multitasking relies on rapid task switching
Single-core processors:
- Were common in older computers
- Are simpler in design
- Can still perform well for simple, sequential tasks
However, as workloads increase, single-core processors become a bottleneck because only one instruction stream can be processed at a time.
Multi-Core Processors
A multi-core processor contains multiple cores on a single chip.
This allows:
- Multiple tasks to run simultaneously
