The need for virtual memory questions and answers
Q1. What is 'memory' in a computer system more properly known as?
A1. Random Access Memory (RAM).
Q2. What is the unit of storage used for RAM and hard drives?
A2. Byte (Kilobyte, Megabyte, Gigabyte etc)
Q3. What limits how much RAM you can have in a computer system?
A3. The motherboard will only be able to work with upto the maximum RAM in its specification.
Q4. What is the hard drive used for in computers?
A4. The hard drive stores all appllications including the operating system and personal files.
Q5. What is meant by ‘virtual memory’?
A5. Virtual memory is when the computer uses some of its hard disk space as if it were RAM.
Q6. What is a Windows 'swap file'?
A6. This is the area on a hard drive that's used for virtual memory.
Q7. Explain how virtual memory works.
A7. What the computer can do is to store all of the applications it possibly can in RAM. It then stores the last little bit of an application it needs on the hard disk. When the CPU needs to run the instructions that make up an application on the hard drive, it first of all frees up some space in RAM. It does this by moving some of the applications in RAM to the hard drive. Then it moves the application it needs from the hard drive to RAM and runs it.
Q8. Which works faster, RAM or a hard drive?
A8. RAM. It's a solid state device. Hard drives are mechanical with moving parts so are slow relatively.
Q9. Explain what ‘disk threshing’ is and why it is a potential problem.
A9. Disk threshing is when you the computer spends too much time swapping files or parts of files between RAM and the hard drive. If you spend a lot of time swapping parts of applications in and out of (fast) RAM to and from the (very slow) hard disk, you may end up slowing the computer right down.
Q10. How much extra space can disk threshing produce without reducing performance too much?
A10. About 5% is considered okay.