CPU

• The bulk of today's CPUs are 64 -bit
• 64-bit CPU architecture

  Incorporates registers that are 64 bits wide
• 64-bit CPUs

  • Allow the CPU to work with and process 64-bit data types and provide support for address space in the terabytes
  • Have been available for PCs since 2003
• 64-bit CPUs

  • AMD FX
  • Intel Core

  
• 32 -bit CPU


  Predecessor to the 64-bit CPU
• Intel started developing well-known 32-bit CPUs with the 386DX CPU


  1985

  
• AMD did likewise with the Am386


  1991
• 32-bit CPU

  Can't support nearly as much address space as a 64-bit CPU, limited to 4 GB
• Most editions of Windows are available in both 32-bit and 64-bit versions
• Processor

  • The most important component on the motherboard
  • The role of the CPU is to control and direct all the activities of the computer
  • Processors are small silicon chips consisting of an array of millions of transistors
• CPU manufacturers

  • Intel
  • Advanced Micro Devices (AMD)
• CPUs

  • Identified by characteristics such as hyperthreading and virtualization support
  • Key characteristics are architecture, speed, and cache size
• Architecture


  • Processors are labelled as 32-bit or 64-bit which refers to the set of data lines between the CPU and the primary memory of the system
  • Another way to discuss architecture is describing the number of cores a processor has such as dual-core or quad-core

  
• Speed

  • Measured in Hertz (Hz) which means electrical cycles per second
  • Modern processors operate at billions (gigahertz, GHz) of cycles per second
• In a single-core processor, the performance of the CPU is limited by the time taken to communicate with cache and RAM, with approximately 75% of CPU time used waiting for memory access results

  
• To improve the performance of their processors, manufacturers have been releasing more multi-core machines
• CPU core


  • A CPU's processor
  • Modern-day processors are predominantly multi-core, with at least two or more cores installed onto an integrated circuit die (or multiple chiplets), allowing them to process two or more tasks simultaneously

  
• Each core can only execute a single task at a time
• Intel uses the term "Core" to brand some of its CPUs, but the numbers you see in an Intel Core (or otherwise) processor is not a direct correlation to how many cores the CPU has

  
• Dual-core, quad-core, hexa-core, octa-core


  Processors with two, four, six, and eight cores respectively

  
• Context Switch Overhead


  When the CPU spends a lot of time switching between tasks, rather than processing them, due to insufficient cores for the number of tasks being processed
• Clock speed


  • A measure of a core's processing frequency, which is not necessarily a measure of its overall performance
  • The number of cycles your CPU executes per second, measured in GHz (gigahertz)
• Sometimes, multiple instructions are completed in a single clock cycle; in other cases, one instruction might be handled over multiple clock cycles
• CPU clock speed is a good indicator of your processor's performance, though applications like video editing and streaming are known to rely on multi-core performance, and many new video games still benchmark best on CPUs with the highest clock speed
• Clock speed

  The number of cycles of calculations that the core runs per second, measured in Gigahertz: billions of cycles per second
• The internal architecture, the synergy between multiple cores, and the size of the internal caches are paramount for producing a CPU's overall performance, not just clock speed

  
• Active workloads


  Processes that need the user to manually manipulate or adjust data in real-time, in order to complete a task, such as interacting with an Application's Viewport in real-time in Motion Design, 3D Modelling, Video Editing, or gaming
• Passive workloads


  Tasks that are usually easily parallelizable and that can be left unattended, such as rendering tasks like CPU or GPU rendering, 3D rendering, video rendering
• Active workloads are more so dependent on high single-core performance and boost clock speeds, while passive workloads benefit from high core counts and higher base clock speeds
• Thread


  • A set of data that is sent from an application to the CPU in order to be processed
  • Not a physical component of the CPU, but an indicator of the amount of processes the cores can handle
  • Threading creates multiple virtual cores out of each physical core (usually two threads per core) to optimize task queueing and utilize the real core more efficiently
• Having the ability to process multiple threads allows your CPU to seamlessly switch between workloads and tasks
• Hyperthreading


  The process of splitting physical cores into virtual cores, allowing a single core to process multiple threads more efficiently
• Logical processors


  A measure of how many Cores the operating system sees and can address, which is the product (multiplication) of the number of physical cores with the number of threads each core can handle

  
• Physical cores are more valuable than logical processors (threads), as logical processors at most will introduce a 50% performance uplift in well-parallelized workloads, while physical cores will show a 100% performance increase

  
• CPU Name Structure

  Five parts: Brand, Tier, Generation, Model, Suffix (Optional)
• Brand


  Pretty intuitive, often omitted when specifying a CPU since the tier includes a brand-specific term (Core for Intel and Ryzen for AMD)
• Tier


  There are four processor tiers within each brand: 3, 5, 7, and 9, indicating performance level
• Placing food into the mouth


  1. First hand looks for more food

  2. Second hand places food into the mouth to be processed
• This is a waste of processing time
• CPU Name Structure


  There are five parts: Brand, Tier, Generation, Model, Suffix (Optional)