A computer architect is designing a new processor and wants to minimize the time taken to access frequently used instructions and data. Which memory hierarchy component should she focus on optimizing for the greatest impact on CPU performance?

A computer's memory hierarchy is designed to provide fast access to data while managing costs, with faster, smaller memory closer to the CPU. To minimize access time for frequently used instructions and data, optimizing cache memory hit rate has the greatest impact on CPU performance. Cache memory is a small, very fast memory located near the CPU that stores copies of data from main memory that the CPU is likely to need next. A high hit rate means the CPU finds the data it needs in the cache more often, avoiding slower main memory access.

• Hard Disk Drive capacity is for long-term storage and is far too slow for direct CPU access.
• RAM clock speed is important for main memory, but cache is even faster and directly serves the CPU's immediate needs.
• Virtual memory page file size relates to disk space used when RAM is full, which is significantly slower than cache.