Four examples of optical storage media are: • DVD-RW • DVD-RAM • CD-ROM • Blu-ray disc The table below shows four features of optical storage media.

Mark scheme

Marking points from the official mark scheme (May/June 2016). The mark or mark type is shown in brackets.

1. [1] (a) DVD-RW: Single track (✓), Red laser used to read/write data (✓)
2. [1] (a) DVD-RAM: Many concentric tracks (✓), Red laser used to read/write data (✓)
3. [1] (a) CD-ROM: Single track (✓), Red laser used to read/write data (✓)
4. [1] (a) Blu-ray disc: Single track (✓), Blue laser used to read/write data (✓)
5. [1] (b)(i) don't need to "get up to speed” to work properly/no latency
6. [1] (b)(i) lower/less power consumption/more energy efficient
7. [1] (b)(i) run cooler
8. [1] (b)(i) run quieter
9. [1] (b)(i) data access is faster
10. [1] (b)(i) occupies less physical space/more compact
11. [1] (b)(i) lighter, so more suitable for a portable computer/laptop
12. [1] (b)(i) no moving parts so more reliable/durable in a portable computer/laptop
13. [1] (b)(ii) HDD is cheaper for larger amounts of storage space
14. [1] (b)(ii) HDD has greater longevity for read/write functions
15. [1] (b)(ii) Expensive to change the technology // HDD are trusted technology
16. [1] (b)(ii) No requirement for the increased speed of SSD