Introduction
When you do any task in computer, it needs a place to store all the data and information it’s using. It store everything in the memory.
Memory Size: Understanding How Computer Data is Measured
Let’s understand how data storage units are measured from smaller to larger data units.
- In computers, data is stored and represented using bits, which are like switches that can be either ‘on’ (1) or ‘off’ (0).
- In 1960s, ASCII (American Standard Code for Information Interchange) character encoding was developed.
- ASCII uses 8-bits to uniquely represent different characters like letters, numbers, and symbols.
- This 8-bit representation became the standard for character encoding.
To simplify calculation, we represented:
- 1-bit (b) = 0 or 1.
- 1 byte (B) = 8 bits.
Data Storage Conversion Table: Easily Convert Bytes, Kilobytes, Megabytes, and More!
| Unit | Size |
|---|---|
| Kibibyte (KiB) | 1,024 bytes |
| mebibyte (MiB) | 1,024 KiB |
| Gibibyte (GiB) | 1,024 MiB |
| --- | --- |
| Unit | Size |
|---|---|
| Kilobyte (KB) | 1,000 bytes |
| Megabyte (MB) | 1,000 KB |
| Gigabyte (GB) | 1,000 MB |
| --- | --- |
Computer Memory: Exploring the Layers of Memory in Computer System
Before discussing about computer hierarchy. Let’s understand, How fast a CPU can process any task?
- CPU is superfast and process billion cycles per second.
- Take an example of 3.2 GHz CPU or Processor, it can execute 3.2 billion cycles per second.
Main goal of having a computer hierarchy is to provide a data storage which can be accessed at the same speed of what CPU requires.
There are 4 commonly used storage available in computer.
Computer Memory Hierarchy: A Comparison from Registers to RAM, Cache, and Storage
| Register | Cache | RAM | HDD or SSD | |
|---|---|---|---|---|
| Speed | Fastest | Faster | Fast | Slowest |
| Cost | Expensive | Costly | Cheap | Cheapest |
| Size | 8 to 64-bit | 64 KB to 32 MB | 1 to 16 GB | 500 GB to 8 TB |
| Store | Temporary | Temporary | Temporary | Permanent |
| Purpose | Super-fast storage for CPU to quickly fetch, execute and process data. | Hold a queue of data and instructions which will be processed next. | Stores the running program and data so that it is ready for use when the CPU needs it. | Long term permanent storage. |
Advantages of Computer Memory Hierarchy
Problem Statement: Enhancing Data Access Speed
Imagine you are listening to songs, working on a document, and browsing the internet simultaneously on your computer.
Problem Description: The Challenge of Different Tasks
Each tasks in computer requires access to different data and instructions.
- If computer store it in the HDD (slowest memory), then accessing this information would be incredibly slow.
- The CPU will be spending time in waiting for data, resulting in a frustrating user experience.
Solution: Introducing the Memory Hierarchy
To tackle this challenge, computers uses memory hierarchy.
- Faster Memory for Frequently Accessed Data:
- Computer organizes the frequently accessed data like operating system, applications (audio player, document editor) in faster memory like cache and RAM.
- This allows the CPU to quickly access all the information to ensure smooth and responsive performance.
- Slower Memory for Less Frequent Data:
- Computer organizes the less frequently accessed data in slower memory types like HDD or SSD.
- While these memory types have slower access time, they offer more storage capacity at a cheapest cost and permanent storage.
