Optical Storage | 2.2 | OCR GCSE Computer Science | J277

8 flashcards

Why is optical storage becoming obsolete? (out of date)

Due to its inferior characteristics compared to magnetic and solid state storage.

What are the 3 types of optical disc?

- CD - DVD - Blu-ray

What is common between CDs, DVDs and Blu-rays?

All have low capacities. - Standard CDs can store 700 MB. - Standard DVDs can store 4.7 GB. - Standard Blu-rays can store 25 GB.

What are the positives for optical discs being cheap to manufacture?

Ideal for mass producing: - Music albums (CDs) - Movies (DVDs) - Games (Blu-rays)

Describe the durability of optical storage.

They are lightweight and portable but need to be protected.

Describe the cost of optical discs compared to optical storage.

- Despite a single disc being cheap (about 20p), optical storage is the most expensive per GB. - It has a very low capacity, so 700 MB for a CD means roughly 28p per GB.

How do optical discs work?

They use a laser beam light onto a spinning disc.

What does a spinning disc mean for an optical disc's access speed, reliability and durability?

It is slow and they can easily be scratched and degraded over time.