1.1.2

• The main factors affecting CPU performance:

  • Clock speed
  • Cache size
  • Number of cores
• Clock speed = the number of instructions a single processor core can carry out per second
• For most desktop computers, their clock speed will be around 3.5GHz (One Hz is one instruction per second, 3.5GHz is 3.5 billion instructions per second)
• Overclocking is where a CPU is made to run at a higher clock speed than the factory-set rate. This can make CPUs overheat, causing crashes or permanent damage to the system
• Number of cores = each core in a CPU can process data independently of the rest, the more cores a CPU has, the more instructions it can carry out at once
• A greater number of cores means that parallel processing can take place, with two or more instructions being executed simultaneously
• However, the computer's software must be designed to use multicore processing or it has no effect on the performance of the CPU
• Cache is data storage inside the CPU that's much faster than RAM. A larger amount of cache means the CPU has faster access to more data so performance is improved
• More RAM can mean a faster computer. If a computer has too little RAM, it may run slowly due to the use of virtual memory
• A Graphical Processing Unit (GPU) can help the CPU process images, relieving the processing load on the CPU and freeing it to do other things
• For better graphics performance, a dedicated GPU is often used
• An embedded system is a computer, designed to be integrated into a larger system or device to perform a specific function
• Embedded systems are often dedicated to one function so are easier to design, cheaper to produce and more efficient at doing their task than a general purpose computer.
• Characteristics of an embedded system:

  • Reliable
  • Minimal resources
  • Programs are typically written in low level languages so it uses minimum memory and executes quickly
  • Very limited operating system, only able to run a single application
  • Very simple user interface or none at all