This deep dive covers Deep Dive: Why We Need All Three Factors 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 2 of 8 in this topic. Use this deep dive to connect the idea to the wider topic before moving on to questions and flashcards.
Deep Dive: Why We Need All Three Factors
Why can't we just increase clock speed forever? In the early 2000s, CPUs hit a wall. Increasing clock speed beyond about 4-5 GHz generates so much heat that the CPU would melt! This is why modern CPUs focus on multiple cores and larger cache instead of just raw speed.
The Power Wall: Doubling clock speed roughly quadruples power consumption and heat generation. At very high speeds, the CPU uses more power for cooling than for actual computing!
Modern approach: Instead of a single 10 GHz core (impossible to cool), we have 8 cores at 3 GHz each. This gives better overall performance while staying cool and efficient. Plus large cache (up to 64MB!) reduces memory wait times.
Practice questions for CPU Performance
What does clock speed measure in a CPU?
Describe three factors that affect CPU performance.