Memory is classified according to its distance from the processor, the closer memory is the slower one

the processor retrieves the data from main memory (DRAM). This is called a cache ..

If the processor requests data that is available in the cache, it is returned quickly. This is called a cache ..

the requested data resides in cache

the requested data is not found

If the cache hits most of the time, then the processor seldom has to wait for the slow main memory, and the average access time is ….

The third level in the memory hierarchy is the ….

In the same way that a library uses the basement to store books that do not fit in the stacks, computer systems use the main memory to store data that does not fit in hard drive

The hard drive provides an illusion of more capacity than exists in the main memory called

Data in virtual memory takes a short time to access

The Main memory/Physical memory can be viewed as a cache for the most commonly used data from the hard drive

Virtual memory increases the memory capacity by using a hard drive to store data that does not fit in the main memory

Caches and virtual memory add complexity and hardware to a computer system, but the benefits usually outweigh the costs

All modern personal computers doesn’t use caches and virtual memory

Most processors also use the memory interface to communicate with I/O devices.This is called memory-mapped I/O

The percentage of memory accesses not found in a given level of memory

The percentage of memory accesses found in a given level of memory

the average time a processor must wait for memory per load or store instruction

In the typical computer system, the processor first looks for the data in the cache. If the cache misses, the processor then looks in main memory. If the main memory misses, the processor accesses virtual memory on the hard disk

the access times of the virtual memory

the main memory miss rates