NST 121 Ch 6

The main memory in a desktop personal computer is made of:

RAM

_______ memory allows data to be both read from and written to easily and rapidly.

RAM

The basic difference between RAM and ROM memory is:

RAM is read/write while ROM Is read only

A unified cache is a cache that holds both data and instructions.

True

All cache mapping schemes require a main memory address to have an offset field.

True

It is important to know if a computer is byte or word addressable because we need to know how many addresses are contained in main memory, cache, and in each block when doing cache mapping.

True

The two types of cache write policies are write-through and write-back.

True

When a computer uses paging, there must be a page table for every process.

True

Cache memory improves performance by improving memory __________ while virtual memory improves performance by increasing memory _____________.

access time/address space

Memory that is accessed by searching for content is called:

associative memory

________ memory is a small, high-speed, high-cost memory that servers as a buffer for frequently accessed data

cache

"Locality of reference" refers to:

clustering of memory references

The average time required to reach a memory storage location and retrieve its contents is called:

effective access time

Memory segmentation can result in _________________ fragmentation, while paging can result in ___________ fragmentation.

external / internal

Information can be retrieved fastest from:

hard disk

The approach of using a combination of memory types to provide the best performance at the bestcost is called:

hierarchical memory

When the requested data resides in a given level of memory, we call this a ________.

hit

The tag field of a main memory address is used to determine:

if the cache entry is the desired block

A major advantage of direct mapped cache is its simplicity and ease of implementation. The main disadvantage of direct mapped cache is:

its performance is degraded if two or more blocks that map to the same location are used alternately

Examples of secondary memory include:

magnetic disk drives and solid state memory

Cache memory is effective because:

of the principle of locality

Which of the following types of memory has the shortest (fastest) access time?

registers

Which of the following types of memory has the longest (slowest) access time?

secondary memory

Cache memory is typically positioned between:

the CPU and RAM

Cache mapping is necessary because:

the address generated by the CPU must be converted to a cache location

The offset field of a main memory address is used to determine:

the location of the desired data in the cache block

All of the following are cache replacement algorithms except:

thrashing

The purpose of a TLB is:

to cache page table entries

Cache replacement policies are necessary:

to determine which block in cache should be the victim block

What characteristic of RAM makes it unsuitable for permanent storage?

volatile

Assuming an 8-bit virtual address with pages of 32 bytes, the virtual address format is:

3 bits for the page and 5 bits for the offset

If a cache access requires one clock cycle and dealing with cache misses requires an additional five clock cycles, which of the following cache hit rates results in an effective access time of 2 clock cycles?

80%

Which of the following types of memory needs to be refreshed periodically to maintain its data?

DRAM

Caching breaks down when programs exhibit good locality.

False