Types of processors

Types of processors

1. RISC: reduced instruction set computer. A RISC processor allows the CPU to execute lower cycles per second.

   • It consists of simple hardware and cannot understand high-level languages, like Python or Java.
   • RISC processors require longer code which means it uses more RAM
   • Every operation is taken place in one cycle
     • Each of these smaller instructions can be carried out in a single clock cycle (ideally), which means it is much simpler to use pipelining to improve performance.
   • RISC processors are used in smartphone and tablets, as they are smaller
     • Fewer transistors needed in the circuitry of RISC
       • Less power consumption
       • Less heat emitted
       • Lower cost
   • By reducing the instruction set, the CPU can access and process instructions faster.
   • RISC processors require very fast memory systems to feed various instructions. Typically, a large memory cache is provided on the chip in most RISC based systems.

2. CISC: complex instruction set computer. The execution of instruction may take many cycles to complete.

   • The primary function of a CISC processor is to complete a task in as few lines of assembly code as possible.
   • Instructions can be completed in one cycle.
     • http://www.ques10.com/p/8587/explain-features-of-risc-and-cisc-processors-2/
     • When executed, this instruction loads the two values into separate registers, multiplies the operands in the execution unit, and then stores the product in the appropriate register. Thus, the entire task of multiplying two numbers (2, 3) can be completed with one instruction: MULT 2, 3
     • Many of the instructions are complex, which means that RAM usage is low.
   • This architecture makes the efficient use of main memory since the complexity (or more capability) of instruction allows to use less number of instructions to achieve a given task.
   • The compiler need not be very complicated, as the micro program instruction sets can be written to match the constructs of high level languages.
   • The overall performance of the machine is reduced because of slower clock speed.
   • CISC processors are larger and more complex, which require more transistors

3. MULTICORE

4. PARALLEL