Must-know Topics on Operating System

Must-know topics on operating system

Table of Contents

1. Basics
2. Memory Management
3. Process Management
4. I/O Management
5. File System

G4G OS

1. Basics

1. 32-bit and 64-bit OS

G4G, techsupport

• Max Memory Access. Two types of the processor: 32-bit and 64-bit (They have 32 bit and 64 bit registers for doing ALU). This processor tells us how much memory a processor can have access from a CPU register. A 32-bit system can access 2³² memory addresses, i.e 4 GB of RAM. A 64-bit system can access 2⁶⁴ memory addresses, i.e 18-Billion GB of RAM. In 32-bit Windows, the total available virtual address space is 2³² bytes (4 gigabytes). Usually, the lower 2 gigabytes are used for userspace, and the upper 2 gigabytes are used for system space.
• Number of calculations per second they can run affects the speed at which they can complete tasks. 64-bit processors can come in dual core, quad core, six core, and eight core versions for home computing. Multiple cores can increase the processing power and help make a computer run faster.
• A computer with a 64-bit processor can have a 64-bit or 32-bit version of an OS installed, However, with a 32-bit operating system, the 64-bit processor would not run at its full capability as the left most 32 bits of the 64 bit registers will not be used.
• On a computer with a 64-bit processor, we can’t run a 16-bit legacy program. Many 32-bit programs will work with a 64-bit processor and operating system, but some older 32-bit programs may not function properly, or at all, due to limited or no compatibility.
• There are three components system that can have 32-bit or 64-bit. To run a 64-bit operating system you need support from the lower level: the 64-bit CPU. To run a 64-bit application you need support from all lower levels: the 64-bit OS and the 64-bit CPU.
  1. Processor or CPU as the central or lowest layer
  2. OS as the middle layer
  3. The application (or the process) as the outermost or highest layer

2. Multiple CPUs, Cores, and Hyper-Threading

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• Hyper-threading was Intel’s first attempt to bring parallel computation to consumer…