Virtualization and Optimization

Virtualization and Optimization
Learning objectives:
• explain the differences between RAM and ROM memory
• explain the purpose of virtual memory and cache memory
Repeat
What is “virtualization”?
Repeat
What is “virtualization”?
 What is “virtualization machine”?
Repeat
What is “virtualization”?
 What is “virtualization machine”?
What are some of the stages of
development of computer
technology?
Repeat
What is “virtualization”?
 What is “virtual machine”?
What are some of the stages of
development of computer
technology?
Why use a virtual machine?
What determines the speed of the
computer?
Main memory - data store that can
be directly addressed by the CPU
Main memory is used to store program instruction
and data, using the System Bus to communicate
with CPU. Main memory is often created using
Random Access Memory (or RAM) or Read Only
Memory (ROM). Modern computers will have
gigabytes of RAM, meaning that large programs
can run and multiple programs can run at once. The
more main memory that you have the larger the
number of programs you can run at once.
RAM - Random Access Memory can be read from and
written to. Data is cleared when the power is off.
ROM - Read Only Memory can only be read from, data is
maintained when the power is off
The two main types of main memory are ROM and RAM. Whilst
RAM might be several gigabytes in size, ROM will often be a few
kilobytes. As ROM is read only memory, it tends to store core
software instructions such as the code needed to load the
Operating System into RAM (known as bootstrapping) or change
the bios. RAM is much much larger and stores the code to run the
operating system and programs that you run on your computer.
When you load a disc into a games console, the code won't do
anything until it has loaded from the disc into the system RAM,
that's why you see a loading screen.
Give a definition for main memory:
Give a definition for main memory:
Main memory is a data store that can be directly
addressed by the CPU
What is the difference between ROM
and RAM?
What is the difference between ROM
and RAM?
ROM is Read Only Memory, RAM is random access
memory. This means that ROM cannot be written
to, it can only be read from. RAM can be both
read from and written to.
Name the four components of Von
Neumann Architecture
Name the four components of Von
Neumann Architecture
Processor
Main memory
I/O devices
System bus
Cache - a memory with higher speed are
designed for faster access to the data
contained in the memory continuously at a
lower speed access.
Кэш — это память с большей скоростью
доступа, предназначенная для ускорения
обращения к данным, содержащимся
постоянно в памяти с меньшей
скоростью доступа.
memory leak
- утечка памяти
uncontrolled process of reducing the amount of free RAM or
virtual memory computer associated with errors in the
programs that are running on time does not relieve the
unnecessary portions of memory already, with mistakes or
system services control memory.
(процесс неконтролируемого уменьшения объёма
свободной оперативной или виртуальной памяти
компьютера, связанный с ошибками в работающих
программах, вовремя не освобождающих ненужные уже
участки памяти, или с ошибками системных служб
контроля памяти.)
garbage collector – сборка мусора
garbage collection was invented by John
McCarthy about in 1959
The program provides a means to automatically
release the unused memory