This document discusses digital devices and their processing and memory components. It describes how the CPU works with a control unit and ALU to fetch, decode, and execute instructions. The CPU has factors like clock speed, number of cores, and cache memory. Memory is volatile RAM for short-term use and non-volatile ROM and hard drives for long-term storage. Storage needs depend on the operating system, applications, data, photos, music and video. Larger storage options include cloud, SSD, multiple hard drives, and external drives.

1. S
Module 2: Digital Devices
Section C – Processing & Memory
CSC 103 Intro to Computing

2. The CPU Subsystem
How the
CPU works…

3. The CPU Subsystem
 Composed of control unit and
arithmetic logic unit (ALU)
 Control unit coordinates activities of all
computer components – “brain” or “boss”
 ALU is responsible for a math operations
and logic comparison operations
 Registers – memory on the CPU used by
control unit & ALU for storing instructions
and data

4. CPU Processes (FDE)
1. Fetches address & data from RAM
2. Decodes instructions from binary
3. Executes the instruction
 Stores result in RAM
before next instruction

5. CPU Factors
 Clock Speed measured in GHz
– billions of steps per second
 Number of cores
- Single, Dual Core, Quad Core
 Cache Memory – Like RAM for the CPU –
temporary storage that speeds up
processing (Level 1, 2 & 3)

6. Evaluating Memory
Volatile
 RAM – Random Access Memory
Volatile temporary
storage – short term
memory – speeds
up instructions
– think of memory
like counter space
when cooking

7. Evaluating Memory
non-volatile
 ROM – Read Only Memory
–non-volatile
- Handles boot instructions, etc.
 Hard Drives – are non-volatile
storage spaces – larger, but slower

8. Memory Speed
Fastest
Access

9. Evaluating Storage Needs
250 GB – 500 GB – 1TB
 The OS – 20-30 GB
 Applications – 50 GB
 Data – 10-20 GB
 Photos – 40-50 GB
 Music & Video – 100-150 GB

10. Larger Storage Considerations
 Cloud Storage
- Can offset some photo, music, video storage
 Flash Storage – SSD Cards & Drives
 Multiple Internal Hard Drives (RAIDS)
- Redundant Array of Independent Disks
 External Hard Drives
better for back-up purposes

11. Hard Drives vs SSD
 Magnetic Hard Drives – Spinning platters
that are magnetized to write data
- Spin at 7200 RPMS, 4TB capacity
- Lots of moving parts, slower
 Solid State Drives – Charged electronic
transistors that store data
- faster, less chance of crashing,
- run cooler, 1 TB capacity

12. Audio & Video
Considerations
 Graphics/Video Cards - hardware that is
responsible of producing output to monitor.
It has a connector(s) for monitor(s) and
another connector to computer motherboard.
 GPU (Graphics Processor Unit) is part of
graphics card and more essential for gaming,
3D software, video editing software (Nvidia
GeForce, AMD Radeon)

13. Purchase Consideration
 Buy what you think you will need
3-5 years from now
 You will only gather more photos, music,
video, software, games
 Operating Systems will require more
space and more RAM with each upgrade