This key facts covers Factor 2: Number of Cores within CPU Performance for GCSE Computer Science. Revise CPU Performance in 3.4 Computer Systems for GCSE Computer Science with 15 exam-style questions and 12 flashcards. This topic appears regularly enough that it should still be part of a steady revision cycle. It is section 4 of 8 in this topic. Use this key facts to connect the idea to the wider topic before moving on to questions and flashcards.
Factor 2: Number of Cores
What It Is:
Modern CPUs have multiple processing units (cores) on a single chip. Each core can execute its own set of instructions independently.
Common Configurations:
- Dual-core: 2 cores (can run 2 tasks simultaneously)
- Quad-core: 4 cores (can run 4 tasks simultaneously)
- Hexa-core: 6 cores
- Octa-core: 8 cores
- High-end: 16, 32, or even 64 cores for servers!
How It Affects Performance:
- Parallel processing: Multiple tasks can run at the exact same time
- Better multitasking: Browse web, listen to music, run antivirus simultaneously without slowdown
- Each core has its own: ALU, registers, L1 cache (but shares L3 cache)
- Example: 4-core CPU can run 4 programs at once, or split 1 program across 4 cores
Important Limitation:
Not all programs can use multiple cores! A program must be specifically written to split work across cores (called "multi-threading"). A single-threaded program on a 4-core CPU will only use 1 core, wasting the others. This is why some old programs run slowly on modern CPUs.
Practice questions for CPU Performance
What does clock speed measure in a CPU?
Describe three factors that affect CPU performance.