Computer System architecture

Computer System Architecture

CompTIA A+ 220-1201 - Core 1 | Lesson 3.5

32-bit vs. 64-bit Operating Systems

A computer's system type (32-bit or 64-bit) refers to the CPU's processing capabilities and addressable memory space.

32-bit processors (x86 architecture) can reference up to 2³² (4 GB) of memory.

64-bit processors (x64 architecture) can reference up to 2⁶⁴ (17 billion GB) of memory

though practical limits are lower.

Key differences:

Hardware drivers must match the OS bit-type (32-bit drivers for 32-bit OS

64-bit drivers for 64-bit OS).

32-bit applications can run on a 64-bit OS

but 64-bit applications cannot run on a 32-bit OS.

Windows stores 32-bit applications in Program Files (x86) and 64-bit applications in Program Files.

ARM Processors

ARM (Advanced RISC Machine) is a CPU architecture designed by Arm Limited

known for efficiency and low power consumption.

Commonly used in mobile devices (99% of smartphones) and increasingly in laptops/desktops.

Key advantages:

Lower power usage and heat output.

High processing speed for lightweight tasks.

Licensed to third-party manufacturers (e.g.

Apple

CPU Cores and Multiprocessing

A CPU (Central Processing Unit) may contain multiple cores

each acting as an independent processor with its own cache memory.

Multi-core CPUs (e.g.

8-core

Each core has:

A dedicated CPU unit.

Local cache memory for faster data access.

Example: A 16-core CPU can execute 16 instructions simultaneously.

End of Notes

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