CPU & System Perfomance

• CPU performance depends on clock speed, cores and cache
• Clock speed - This is the number of instructions a single processor core can carry out per second (Hz)
• Clock speed - For most computers, this will be somewhere around 3.5GHz (3.5 billion instructions per second)
• The higher the clock speed, the greater the number of instructions that can be carried out per second
• Each core in a CPU can process data independantly of the rest
• 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 these days
• 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
• It's not quite as simple as doubling the number of cores doubles performance. Software needs to be designed to use muilticore processing
• Not all processing tasks can be split evenly between cores
• Generally speaking, CPUs with higher clock speeds, more cores or larger caches will have better performance, but will also be more expensive
• More RAM can mean a faster or smoother system
• RAM comes on sticks which plug into slots on the motherboard

  
• If a computer has too little RAM it may run slowly due to the use of virtual memory
• The more RAM, the more applications or more memory-intensive applications it can smoothly run, making it faster overall
• It's easy to upgrade RAM on a PC or a laptop - just replace the RAM sticks with higher capacity or higher speed ones
• If the computer already has plenty of RAM to run everything the user wants, increasing the RAM may make no difference to performance
• GPUs help CPUs process images
• GPU = Graphics Processing Units
• GPUs are specialised circuits for handling graphics and image processing
• GPUs relieve the processing load on the CPU, freeing it to do other things
• Computers have basic GPUs integrated onto the motherboard or the CPU
• For better graphics performance, a dedicated GPU (graphics card) is often used
• Using high-end graphics cards can greatly improve performance in graphics-intensive applications e.g. PC gaming and design software
• This is a GPU

  A) PCI interface slots in motherboard

  B) cooling fans

  C) video outputs