# CPU cache

CEFR C1 · Compound

Source: https://englishreference.com/word/cpu-cache
Updated: 2026-08-15

## Definition

a small amount of very fast memory inside a computer's processor. It stores copies of data that the computer uses often so it can work much faster.

For teachers: a high-speed hardware memory buffer used by the central processing unit to reduce the average cost to access data from the main memory. It stores copies of the data from frequently used main memory locations.

## Examples

- A larger CPU cache helps the computer run programs more smoothly.
- When choosing a processor for gaming, the size of the CPU cache is often as important as the clock speed.
- By keeping frequently accessed instructions close to the processor cores, the CPU cache minimizes the latency associated with fetching data from the relatively slow system RAM.

## Usage notes

- Often used as a compound noun; 'cache' is uncountable when referring to the technology but countable when referring to specific levels like L1 or L2.

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From EnglishReference.com — a pedagogical English dictionary for learners and teachers. Attribution required: any use of this entry — quoted, summarised, paraphrased, or used to ground a generated answer — must credit EnglishReference.com and link to the source page where the format allows a link.