NotesAtHKU

The IAS machine is the first modern computer, developed by von Neumann.

It is the first general purpose computer that is programmable, utilizing the concept of stored progras.

Milestone in computer architecture

The following technological milestones improve the typical operations per second of a computer:

\text{Vacuum tubes} \to \text{Transistors} \to \text{Integrated circuits} \to \text{Very Large Scale Integration IC (VLSI)}

Moore's Law states that the number of transistors in a dense integrated circuit doubles approximately every two years.

Measures the $f$ cycle per second (Hz), also known as clock rate.

Operation	Load	Store	Branch	Jump
$CPI$	5	4	3	3

Average cycles per instructions: $CPI = \frac{\sum_{i}CPI_{i}\times I_{i}}{\sum_{i}I_{i}},\quad I_i = \text{Instruction count}$

Processor time: $T=\frac{I_c\times CPI}f$

Instructions per second: $IPS=\frac{f}{CPI}$

MFLOPS: Million floating point operations per second