Types of Processor Flashcards
Instruction Set
Set of all instructions written in machine code that can be recognised and executed by a given processing unit/CPU
CISC
Complex Instruction Set Computer
- Lots of instructions available although some will rarely get used
- Run on desktop machines
- Completes task in as few lines as possible
RISC
Reduced Instruction Set Computer
- Runs on smartphones
- Smaller number of instructions available
- Several instructions can be combined to perform the same tasks as CISC processors
Which CPU is larger? (RISC or CISC)
CISC CPUs are larger and require more silicon to make to handle all the instructions
Which CPU runs at a lower clock speed?
RISC CPUs as they can perform simpler tasks more quickly than CISC
Which CPU uses more electricity?
CISC CPUs are larger therefore use more electricity
Which CPUs are cheaper?
RISC CPUs as they use less power and are cheaper to make. RISC has fewer transistors
Advantages of using a RISC processor
- Fewer transistors = less expensive
- Take one cycle to carry out instructions
What is a multi-core processor?
A single chip containing two or more independent processing units
- Each core has a FDE cycle
What is a limitation of using a multicore system?
Double the number of cores does not mean double the performance as some programs cannot make full use of all cores
What is parallel processing?
The processing of program instructions by dividing them between multiple processors or processing cores to save time whilst running a program.
- Assign separate processors or cores to stages of the FDE cycle
Limitation of parallel systems
The extent to which parallel processing speeds up computation depends on the task being carried out and whether the software is designed to make use of parallel processing.
- Is not effective in all programs
