CPU Performance Flashcards
All 7 cards in this deck
What effect does increasing the clock speed have on CPU performance?
More Fetch-Execute cycles are carried out per second, so more instructions are processed in a given time.
What effect does a larger cache have on CPU performance?
More frequently used data and instructions are held close to the processor, so it spends less time waiting for them to be fetched, improving speed.
What is a CPU core, and what effect does having more cores have on performance?
A core is a processing unit that can fetch, decode and execute its own instructions; more cores allow more instructions to be processed simultaneously.
What are the steps to decide which of two CPU specifications will perform better for a stated purpose?
e.g. CPU A: 4 cores, 2.0 GHz; CPU B: 2 cores, 3.2 GHz — for video editing software that uses all cores- Compare each characteristic: A has more cores, B has the higher clock speed.
- Match them to the task: video editing splits work across cores.
- Choose and justify: CPU A, as more instructions are processed simultaneously.
True or false? The CPU with the higher clock speed will always be the better performer.
False. Cache size and number of cores also affect performance, so a slower CPU with more cores or a larger cache may perform better.
What is clock speed, and what unit is it measured in?
The number of clock pulses (cycles) per second, measured in hertz (Hz), usually gigahertz (GHz): billions of cycles per second.
Why might a CPU with twice as many cores not run a program twice as fast?
Extra cores only help if the program is written to share its work between them. Even then, some instructions need the results of earlier ones, so they cannot run at the same time.