Tuesday, September 14, 2010

ITGS Notes #5: CPU and Memory

CPU: Microprocessor

  • interprets and executes the instructions in each program
  • supervises arithmetic and logical data manipulations
  • arithmetic: responsible for numbers and mathematical equations
  • communicates with all the other parts of the computer system indirectly through memory
  • an extraordinary, complex collection of electronic circuits
  • housed along with other chips and electronic components on the motherboard
Compatibility: 
-all software is not necessarily compatible with every CPU 
  • software written for the PC family of processors used in Macintosh computers won't run on Intel processors
  • CPUSs in the same family are generally designed to be backward compatible
  • Newer processors can process all of the instructions handled by earlier models. 
Performance: 
  • applications require faster machines to produce satisfactory results
  • all computers' overall performance is determined by it's microprocessor's internal clock speed
  • Clock Speed: measured in units called Gigahertz for billions of clock cycles per second
The  architecture and word size of the processor 
  • high end work stations and servers use 64-bit processors
  • most PCs and macintosh use 32-bit processors
  • some embedded and special purpose
  • computers still use 8 and 16 bit processors
Techniques for speeding up a computer's performance: 
  • parallel processing 
  • server clusters
A custer is a way the processing resources of multiple servers are grouped together.

The CPU: How it works?
  • ALU (arithmetic logic unit): actual execution of instruction is performed by the ALU
  • Prefetch Unit: instructs the bus unit to read the instruction stored at a particular memory address
  • Decode Unit: takes the instruction read by the prefetcher and translates it into a suitable for the CPU's internal processing.
  • Writeback: the bus unit writes the results of the instruction back into memory ot to some other device

No comments:

Post a Comment