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04 - Virtual Memory

 1. What is virtual memory?

  Long-term memory

  A memory management technique that creates the illusion of a very large (main) memory

  Large secondary memory

  Process for encoding information

 2. Where is data stored when it is in virtual memory?
vm1.png

  RAM

  An optical drive e.g. CD

  ROM

  A secondary storage device e.g. hard disk drive

 3. When several programs run at the same time, the RAM can be full. Instead of closing programs, the operating system uses virtual memory to store some data.

  True

  False

 4. Read/Write speed of a hard disk drive is faster than RAM.
vm2.jpg

  TRUE

  FALSE

 5. Fill in the blanks. 
Because of virtual memory, the memory can be shared 
among___________________.

  instructions

  processes

  none of the mentioned

  threads

 6. Hard drive failure rates are measured with MTBF (Mean Time Between Failures). Which of these failures would be reason to replace your current hard disk?

  Application removal

  Head crash

  Can't read CDs

  File delete

 7. Fill in the blanks. 
A virtual memory block is known as page, and a virtual-memory miss is 
called a________________.

  memory fault

  page miss

  page fault

  hit miss

 8. Effective access time is directly proportional to:

  hit ratio

  page-fault rate

  memory access time

  none of these mentioned

 9. Virtual memory frees applications from managing shared memory and saves users from adding more memory modules when RAM space runs out.
vm3.jpg

  TRUE

  FALSE

 10. Fill in the blanks. 
The address location in the main memory, is referred to 
as____________________.

  static address

  logical address

  block associative

  physical address

 11. A process is thrashing if:

  it is spending more time paging than executing

   page fault occurs

   swapping cannot take place

  it is spending less time paging than executing

 12. Fill in the blanks. 
Virtual memory is normally implemented by ______________.

  buses

  demand paging

  virtualization

  all of the mentioned

 13. The use of virtual memory slows a computer because data must be mapped between virtual and physical memory, which requires extra hardware support for address translations.

  FALSE

  TRUE

 14. The first hard disks, created in the 1950s, could be up to 20 inches in diameter. Which company invented the hard disk?
vm4.jpg

  Intel

  IBM

  HP

  Xerox

 15. When purchasing a hard disk which of these is generally NOT a specification that would be of concern?

  seek time

  capacity

  data rate

  mounting holes


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