11. Comparing Backing Storage

 

The table below compares the storage capacity, access speed, portability and media cost of different types of drive.

Drive Capacity Transfer Speed Portable Drive Cost Media Cost Floppy Disk Low Slow Yes Very low Very low Hard Disk Very High Very Fast No Low/Medium N/A Tape Very High Fast Yes High Low CD High Fast Yes Low CD -R Very Low CD -RW Low DVD Very High Fast Yes Low/medium DVD R Low DVD RW Low USB Flash High Fast Yes Low/medium

 

This table features typical information from 2004 about actual drives. Everything is much cheaper now and you can use it to compare how prices, sizes and transfer speeds have changed over time.

 

Drive Capacity Transfer Speed Drive Cost Media Cost Floppy Disk 1.44 MB 0.04 Mbps £5 10p per disk Hard Disk 100GB Approx 6,000 FD's 100 Mbps £50 N/A Tape 30GB Approx 2,000 FD's 10 Mbps £370 £50 CD 700 MB Approx 500 FD's 30 Mbps £25 CD -R 13p CD -RW 40p DVD 9 GB Approx 6,300 FD's 30 Mbps £70 DVD R £1.50 DVD RW £2.50 USB Flash 256 MB Approx200 FD's 1 Mbps £45 N/A

 

Key

MB = Megabytes
GB = Gigabytes
Mbps= Megabits per second
R = Recordable
RW = Rewriteable
FD = Floppy disks
FDD = Floppy disk drive

 

 

What you have to do!

In your Word document or your Brain answer the following questions.

1. Why are backing storage devices needed in a computer system?
   
   
2. What are the characteristics or criteria you would use to choose between different types of backing storage?
   
   
3. Why are CD's and DVD's sometimes called optical disks?
   
   
4. You are working on a multimedia presentation and would like to work on it at home. Which backing storage system would you use to take it home?

Give reasons for your choice.

 

What you should be able to do!

1. Explain why backing storage is needed in a computer system..

2. Describe the criteria you would use for choosing between each type of backing storage.

 

Continue to 12: Specialised Devices