In a typical computer system, cache memory is a small, high speed memory that acts as an intermediate buffer between which two main components?

Introduction / Context:
Cache memory is an important concept in computer architecture that significantly improves system performance. It is a small but very fast memory designed to bridge the speed gap between the processor and main memory. This question checks whether you understand where cache is logically placed in the memory hierarchy and which components it connects. Recognising the role of cache will help you answer many questions about performance, CPU design and memory systems.

Given Data / Assumptions:

• The focus is on cache memory in a computer system.
• The question asks between which two components cache memory acts.
• Options mention CPU and hard disk, RAM and ROM, CPU and RAM and other unrelated pairs.
• We assume a standard architecture where cache sits near the CPU.

Concept / Approach:
Cache memory is a small, high speed memory located close to or inside the CPU. Its main purpose is to store copies of frequently accessed data from main memory (RAM), so that the processor can access this data more quickly. This means cache acts as a buffer between the very fast CPU and the slower main memory. When the CPU needs data, it first checks the cache; if the data is present, the access is much faster than going to RAM. While there are also disk caches, the term cache memory in basic computer architecture almost always refers to cache between CPU and RAM. Therefore, the correct answer is that cache memory acts between the CPU and main memory (RAM).

Step-by-Step Solution:

Verification / Alternative check:
Computer architecture diagrams show the CPU connected to one or more levels of cache (L1, L2, sometimes L3), which are then connected to main memory. Hard disk drives are shown further away, connected through controllers and buses. Textbooks explicitly state that cache is used to speed up access to main memory by the processor. They may also mention separate disk caching, but that is considered part of storage subsystems, not the central cache memory discussed in basic theory. This repeated description confirms that cache memory sits between the CPU and RAM and acts as a buffer between them.

Why Other Options Are Wrong:

• Central Processing Unit (CPU) and hard disk drive: There may be disk caching, but cache memory in CPU design normally refers to a buffer between CPU and RAM, not CPU and disk.
• Random Access Memory (RAM) and Read Only Memory (ROM): ROM is not typically connected through cache, and this pair does not describe the main function of cache.
• Keyboard and monitor: These are input and output devices and have nothing to do with cache memory placement.
• Network interface card and router: Network buffering is different from CPU cache; cache memory by this name does not sit between these components.

Common Pitfalls:
Because the term cache is sometimes used loosely for different speed up mechanisms (like web browser cache or disk cache), learners may wrongly associate cache memory directly with hard disks. To avoid this, link the phrase cache memory in exam questions to the CPU and RAM hierarchy. Remember that cache memory in architecture is about making main memory accesses faster for the processor, not about storage devices like hard disks. With this mental picture, you can confidently choose CPU and RAM whenever the question refers to where cache memory acts in the system.

Final Answer:
Cache memory acts as a high speed buffer between the Central Processing Unit (CPU) and main memory (RAM).