IGCSE ICT 0417 - Types and Components of Computer Systems

Backing Storage

Backing storage, also known as secondary storage, is a crucial component of a computer system. It's used to store data and programs that are not actively being used by the computer's central processing unit (CPU). Unlike primary storage (like RAM), backing storage is non-volatile, meaning it retains data even when the power is turned off.

Characteristics of Backing Storage

Here's a breakdown of the key characteristics of backing storage:

• Non-volatile: Data persists even without power.
• Larger Capacity: Typically offers significantly more storage space than primary storage.
• Slower Access Speed: Generally slower to access data compared to RAM.
• Cost-Effective: Usually less expensive per unit of storage than primary storage.

Types of Backing Storage

There are several types of backing storage commonly used in computer systems:

• Hard Disk Drive (HDD):
• Solid State Drive (SSD):
• USB Flash Drive (Pen Drive):
• Memory Cards (SD Cards, microSD Cards):
• Optical Discs (CDs, DVDs, Blu-ray Discs):
• Cloud Storage:

Comparison of Backing Storage Types

The following table provides a comparison of different types of backing storage:

Storage Type	Capacity	Access Speed	Cost	Portability	Durability
Hard Disk Drive (HDD)	High	Slow	Low	Low	Moderate
Solid State Drive (SSD)	High	Fast	High	Moderate	High
USB Flash Drive	Moderate	Fast	Moderate	High	High
Memory Card	Low to Moderate	Fast	Low to Moderate	High	High
Optical Disc (CD/DVD/Blu-ray)	Low to Moderate	Slow	Low	Moderate	Moderate
Cloud Storage	Variable (Scalable)	Fast (dependent on internet connection)	Variable (Subscription based)	High	High (data redundancy)

Further Considerations

The choice of backing storage depends on various factors, including the required capacity, speed, portability, and budget. SSDs are increasingly becoming the preferred choice for primary storage due to their faster access times and durability, while HDDs remain a cost-effective option for large-capacity storage.