3.9.1 Processor Concepts

Learn the specifics behind the role and function of a processor.

The processor, or the CPU is an integrated circuit that contains millions of logic gates, connected by hairline aluminum strands. The logic gates work together to store and manipulate data.

The CPU can accept instructions (aka programs) and execute them to perform arithmetic and logical operations, among other tasks.

• prompt the user to enter a series of numbers
• read the input from the keyboard as the user types them
• store those numbers in specific memory locations in the Random-Access-Memory
• add the numbers together, then write the result to a new location in the RAM
• write a:
  • message to the screen
  • file containing the result

Clock Speed

The CPU's clock speed is the rate at which the CPU can execute instructions, measured in gigahertz (GHz). The CPU requires a fixed number of clock ticks to execute each instruction. In general, the higher the clock speed, the faster it can execute instructions.

The clock speed is very important in the CPU, since all the components connected to the CPU through the motherboard also need to be synchronized to this same clock speed.

Overclocking

Overclocking is the act of pushing a CPU beyond it's designed specifications. Users do this to get an increase in performance. Manufacturer Intel has something called Turbo Boost that allows their processors to dynamically run above their specified clock speed.

Since the internal clock timer of the system is higher, all the components connected are also running at a faster rate. However, the heat generated increases dynamically, and the lifespan of the components drains at a faster rate. The overclocked system will also consume more power than one running at normal clock speed. Overclocking your system for long periods of time can lead to system instability.

Cache Memory

The CPU cache is another place the PC stores data, alongside from the hard drives and RAM. For the CPU, accessing the CPU cache is faster than accessing the RAM, so the CPU often stores copies of values stored in the RAM to improve performance.

Cores

In the olden days, CPUs only had one core. For performance increases, users had to buy a special type of motherboard that had two CPU sockets. Today, however, CPU's come with multiple cores. For every core a CPU has, that's one more instruction it can execute at a time. 4 core CPU => 4 executed instructions at the same time

Multithreading

In addition to CPU's supporting multiple cores, some CPU's allow multithreading, which allows one CPU core to execute two instructions at the same time. Some Intel processors have a feature called hyperthreading. CPU cores that have hyperthreading enabled appear to the system as two individual processors for each physical core, which allows each core to execute two instructions at the same time. Hyperthreaded cores can also share system resources, just in case system resources are thin.

Hyperthreading provides a ~20% increase in system performance.

GPU

A graphics processing unit is a chip responsible for handling display functions, like:

• image rendering
• playing animations
• playing videos An integrated GPU shares the physical chip with the CPU.

Virtualization

The ability to install and run multiple OS's on the same physical machine. Can be used to host multiple servers on the same computer, and each VM acts like it's on machine under the host OS.

Cooling

Heat + PC = bad. Cooling methods include:

• heatsink
• heat pipes
• fan
• thermal paste (always do this)
• liquid cooling
• fan-less cooling system

Selection

Intel:

• better performance
• more expensive
• the bigger company AMD:
• not better performance aka worse performance
• less expensive

#III #Aplus