Computer System Flashcards
Computer system
A system that consists of hardware + software
system software
Software that controls hardware + manages all software in a computer system
Application software
Everyday programs that help a user perform specific tasks
fetch
Value in program counter copied to MAR - value is memory address of instruction
Instruction fetched by control unit from main memory and copied into memory data register
decode
Control unit decodes instruction + prepares for next step by sending signals to components that need to be used
execute
Instruction is carried out, e.g. ALU can carry out a calc, or value in PC can be changes. PC also increments
dIfferences between Solid state storage media and magnetic storage media
- magnetic media is slower, as data has to be read w a moving read/write head - data can be scattered
- SSD more compact, smaller size enables mobility
- SSD silent
CPU PARTS
CU, ALU, cache, clock, buses
clock speed
- disadvantage of high clock speed
number of instructions a single processor core can carry out per second
- higher clock speed, MORE INSTRUCTIONS CARRIED OUT PER SECOND
- however, if too hight CPU’S can overheat, crash, damage to the system = you need high performance cooling systems
CPU CORES
- disadvantages
More cores = instruction can run in parallel/simultaneously ,therefore more instructions carried out at once
- however software needs to be designed to use multicore processing, all processing tasks cant be split up evenly, cores will have to wait for each other
Cache size
- larger = CPU has faster access to more data
Cache type
diff levels of cache memory, l1,2,3
- HIGHER LEVEL = slower as further away from CPU, but it can hold more
- L1 on CPU itself, but cant be that large
cpu performance = ram
- too little RAM, may not be able to keep all application data loaded at once = slower system
- MORE RAM = more applications, can smoothly run
- extra RAM than needed will make no difference
