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Types of processor - Coggle Diagram
Types of processor
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CISC and RISC
CISC
Complex Instruction Set Computing. CPUs which carry a rich and full instruction set. Any instruction a programmer might require is there. Having all of these instructions available means that a programmer can write tight and efficient code.
Large instruction set = large and complex CPU with many transistors.
instructions are built into hardware.
Used in embedded systems and microprocessors.
Transistors use up power and generate heat, CPU requires additional cooling. CISC CPUs are built with a heat sink and/or fan which makes them larger in size than a RISC CPU.
Complex instructions can take several clock cycles to complete. They take time to process.
RISC
Reduced Instruction Set Computing.
Frequently used instructions are available. CPU can access and process instructions faster.
Fewer transistors needed to handle the smaller CPU instruction set. RISC CPUs tend to be smaller in physical size than CISC CPUs.
Fewer transistors = lower power consumption, less heat and lower cost.
Smaller, simpler instruction set.
Instructions available are one line of machine code.
Used in everyday devices.
Smaller instructions can be carried out in a single clock cycle, it is simpler to use pipelining to improve performance.
Fewer instructions available, the compiler has to generate more lines of machine code to do the same task that could have been done with one instruction by using a CISC CPU. Need more memory to store the additional instructions that are created.
Comparison
CISC:
complex hardware
fewer registers
more cycles per instruction
less programming code
full instruction set
less memory/RAM as a single instruction can do a complex task
more transistors
used in desktop PCs, laptops
Compilers have to do less work.
RISC :
simpler hardware
many registers
single clock cycle for an instruction - Pipelining is possible.
more programming code
frequently used instructions
more memory as more instructions need to be stored for a complex task
fewer transistors than CISC
used in smartphones, tablets