1. Computer Development Flashcards
What are the four main subcategories of computational devices?
PCs, servers, supercomputers and embedded computers.
What is Moore’s Law?
Moore’s law states that the number of transistors per microchip doubles every two years.
What is the difference between a gibibyte and a gigabyte?
A gibibyte is 1024 mebibytes and a gigabyte is 1000 megabytes.
What is a PMD?
Personal Mobile Device: a small wireless device that connects to the Internet. They are battery-powered and software is installed by downloading apps.
How does Moore’s law affect design of technology?
Designers must design in accordance with how advanced technologies will be when they finish the project.
What is abstraction in computer design?
Hiding away details from the user to make interfaces simpler.
Why should designers spend time optimising the common case, but not necessarily the rare case?
The rare case is often much harder to optimise than the common case.
What is parallelism?
The multiple instances of a certain program.
What is pipelining?
The ‘staggering’ of parts of a process, so that different processor parts can be running in parallel.
What is performance via prediction?
Where computations are carried out before knowing if they will be required.
What is a hierarchy of memories?
The smallest memory is placed in the primary spot, and then subsequent memories in order of size. The smallest memory should be the fastest to access, and they get slower as the memory size increases.
What is dependability via redundancy?
We make systems dependable by including components that take over when systems fail or to help to detect failures.
Give three roles of the Operating System (OS).
Handling basic input and output operations.
Allocating storage and memory.
Providing for protected sharing of the computer among multiple applications using it simultaneously.
What is the function of the assembler?
To convert programs to binary instructions.
What are the three main benefits of high-level languages?
- The programmer can think in a more natural language; using English words and algebraic notation. This means more specific languages can be developed.
- Much quicker to develop programs written concisely.
- The programs are independent of the computer on which they were written.
What are the five classic components of a computer?
Input, output, memory, datapath and control.
What is an ISA?
The list of instructions a processor can perform, as well as the I/O devices present. It means that many implementations of varying cost and performance can run the same software.
Classify main / primary memory and secondary memory as volatile or non-volatile.
Main memory / primary memory are volatile and secondary is non-volatile.
Compare DRAM and SRAM.
DRAM and SRAM are: non-volatile, and have a smallest write of a byte. They also require high power.
DRAM is cheaper than SRAM, but is not quite as fast at reading/writing, and has a smallest read of a page (instead of a byte). DRAM also needs regular refreshing.
Define response/execution time.
The total time required for the computer to complete a task, including all memory accesses, I/O activities and CPU time
Define throughput/bandwidth.
The number of tasks per unit time.
Computer X takes 1ns to compute a sum. Computer Y takes 4 times this. What is the performance of Computer Y?
0.25 s-1
Compare CPU time, user CPU time and system CPU time.
- CPU time is the total time spent in a task.
- user CPU time is the time spent in a program itself.
- system CPU time is the time spent in the OS performing tasks for the program.
State the relationship between clock rate and clock period.
clock rate = 1/(clock period)
(CPU clock cycles for a program)/(Clock rate) = ?
CPU execution time
Instructions for a program x CPI = ?
CPU clock cycles for a program.
Time = Instructions/? x Clock cycles/? x Seconds/?
Instructions/Program x Clock cycles/Instruction x Seconds/Clock cycle
Why is execution time the only valid and unimpeachable measure of performance?
No other metric covers all the factors affecting performance.
