Computing

Computing

1. The CPU

   • Brain of computer system
   • Processes all data and instructions
   • Processing power depends on:
     • Clock Speed
     • Number of cores
     • Cache size
   • 3 Main Parts
     • Control Unit
     • Arithmetic Logic Unit
     • Cache
   • Does fetch decode execute
     • Copies memory address from program counter

2. Memory

   • RAM is high speed and is used as the main memory in a computer
   • When a computer boots up, the operating system is copied from secondary storage to RAM
   • RAM is slower than the CPU cache but way faster than secondary storage
   • Virtual memory is a slow version of RAM
   • ROM tells the CPU how to boot up

3. CPU performance depends on clock speed, cores and cache

   • Clock Speed
     • Number of instructions a single processer core can carry out per second
     • Higher the clock speed, the greater then number of instructions per second
   • Number of cores
     • Each core in a CPU can process data independently
     • The more cores a CPU has, the more instructions it can carry out at once, so the faster it can process a batch of data
     • Most PCs and smartphones have 4 or more cores
   • Cache size
     • The cache is data storage inside the CPU that's much faster than RAM
     • A larger CPU cache gives the CPU faster access to more data it needs to process