Types of Processors
The speed of processor is also measure as millions of instructions per second (MIPS). Computers can process instruction with a speed of more than 300 MIPS.
Two designs of CPU are as follows:
CISC: CISC stands for complex instruction set computing. It supports a large number of instructions. It executes complex instruction more quickly. It is mostly used in PC and conventional mainframe computers.
RISC: RISC stands for reduced instruction set computing. It reduces the instructions: to only those used more frequently. It executes simple instructions more quickly than CISC CPU. It is mostly used in workstations. The workstations can work up to 10 times faster than most PCs due to RISC. It is used in many Macintosh computers.
In some computers, the processor fetches, decodes, executes and stores only one instruction at a time. The CPU waits until an instruction completes its all four stages and then executes the next instruction.
Pipelining is a technique in which CPU fetches next instruction before the completion of the first instruction. It results in faster processing. Most modern computers support pipelining.