1.1.2 Types Of Processors

• is a group of commands for a CPU in machine language • the instruction set will vary from one processor to the next • there are 2 types of processors : - CISC - RISC

• Consists of a larger instruction set which includes more complex instructions [1] • As the instructions are more complex, they can take multiple clock cycles to execute. [1] • instructions are built into the hardware • instructions take up less space in memory - eg. MULT A,B (requires much less lines of code compared to RISC)

• consists of a smaller instruction set with more simple instructions [1] • each instruction is one line of machine code • so takes one clock cycle per instruction [1] • so suited to pipelining • usually used in smartphones and tablets

• has fewer transistors [1] • so require less power [1] • so increase their power efficiency making them ideal for usage in low-power devices like mobile phones • cheaper to manufacture • has fewer general purpose registers • because RISC has simpler instruction set, instructions can be executed faster and so programs run faster • takes up more space In memory / requires more RAM to store the code (as there is more lines of codes) • suited to pipelining so more instructions can be executed in the same amount of time so programs run faster

• has more transistors • so requires more power • has more general purpose registers • used in laptops and desktops • Has more addressing modes • compilers are less complicated • takes up less space in memory/ less RAM required since code is shorter • more expensive to manufacture • not suited to pipelining so programs run more slowly

• a program written for a RISC processor won’t work on a CISC processor vice versa • a program written for a RISC processor won’t necessarily work on another RISC processor as they may have different instruction sets

• is a co-processor made of lots of Independent processors • the GPU is responsible for processing graphics within the computer to reduce load on the CPU • a GPU can either be part of the graphics card or embedded in the CPU

• CPUs are general purpose processors whereas GPUs are specifically designed for graphics [1] • GPUs are likely to have built in circuitry or instructions for common graphics operations [1] • GPUs can perform an instruction on multiple pieces of data at one time [1] • this is useful when processing graphics • e.g transforming points on a polygon or shading pixels • this means it can perform transformations to onscreen graphics quicker than a CPU

• 3D modelling • Data modelling • financial modelling • Data mining • machine learning • calculations on multiple data at the same time

• a computing method that enables processing of multiple data with a single instruction • GPUs support SIMD processing as they are designed to perform the same operation on multiple pixels or vertices simultaneously • this is a common requirement in image processing, simulations and machine learning

• it isn’t possible to use only a GPU as the CPU assigns tasks to the GPU • parallel processing : GPUs can handle many tasks simultaneously as they are multicore processors • faster execution: as GPUs can use parallel processing, they can speed up tasks, particulary involving large amounts of data or complex computations. • GPU’s can perform more calculations per unit of power consumed in comparion to CPUs making them more energy efficient when it comes to parallel tasks

• A multi-core system has multiple cores (processing units) in a single processor which can each independantly process instructions concurrently • when a computer has multiple cores, it can utilise parallel processing

• Definition: Cores work together on the same task or on separate tasks concurrently. • Application: Enhances efficiency by dividing tasks among cores.

• using multi-core processors • utilising more than one processor eg. CPU and GPU

• Multitasking: Definition: Each core handles a different task simultaneously. ( this is useful when a user has multiple applications open at the same time ) • Background Tasks: Issue: Single processor systems can slow down with background tasks. Solution: Multicore processors allocate background tasks to separate cores. • Improved Responsiveness: Advantage: Even if a program becomes unresponsive, other tasks continue smoothly on other cores.

• RISC has a smaller instruction set [1] • requires fewer transistors [1] • so requires less power [1]