RAM (RANDOM ACCESS MEMORY)

RAM (RANDOM ACCESS MEMORY)

WHAT IS RAM?

    -   RAM (Random Access Memory) is the hardware location in a computer where the operating system, application programs, and data in current use are kept so that they can be quickly reached by the computer's processor.

    -    RAM is much faster to read from and write to than most other kinds of storage in a computer (the hard disk, floppy disk, and CD-ROM). However, the data in RAM stays there only as long as it has power.

    -    When you turn the computer off, RAM loses its data. When you turn your computer on again, your operating system and other files are once again loaded into RAM, usually from your hard disk.

RAM is short-term memory and the hard disk is a long-term memory. The short-term memory focuses on work at hand, but can only keep so many facts in view at one time. if RAM fills up, the processor needs to continually go to the hard disk to overlay old data in RAM with new, slowing down the computer's operation.

    -   Every computer comes with a small amount of ROM that holds just enough programming (BIOS) so that the operating system can be loaded into RAM each time the computer is turned on.

    - RAM is acronym used for Random Access Memory. Virtually all the computers now or then depend on memory to perform all its functions. Without RAM it becomes impossible to get very far, from the moment the Computer is turned ON. The software applications installed on the computer depends largely on the RAM. It is responsible for holding the data while any application is running. Once the application is closed without saving, the data gets lost.

HOW THE DATA IN RAM IS ACCESSED

-  When the processor or CPU gets the next instruction it is to perform, the instruction may

contain the address of some memory or RAM location from which data is to be read

(brought to the processor for further processing). This address is sent to the RAM

controller.

-  The RAM controller organizes the request and sends it down the appropriate

address lines so that transistors along the lines open up the cells so that each capacitor

value can be read. In DRAM a capacitor with a charge over a certain voltage level

represents the binary value of 1 and a capacitor with less than that charge represents a 0.

For dynamic RAM, before a capacitor is read, it must be power-refreshed to ensure that

the value read is valid. Depending on the type of RAM, the entire line of data may be

read that the specific address happens to be located at or, in some RAM types, a unit of

data called a Page is read. 

-  The data that is read is transmitted along the data lines to the processor's nearby data buffer known as level-1 cache and another copy may be held in level-2 cache. For video RAM, the process is similar to DRAM (Dynamic RAM) except that, in some forms of video RAM, while data is being written to video RAM by the processor, data can simultaneously be read from RAM by the video controller. example, refreshing the display image.

DYNAMIC RAM (DRAM)

DYNAMIC RANDOM ACCESS MEMORY has memory cells with a paired transistor and capacitor requiring constant refreshing. Because reading a DRAM discharges its contents, a power refresh is required after each read. Apart from reading, just to maintain the charge that holds its content in place, DRAM must be refreshed about every 15 microseconds. This simple architecture makes DRAM the least expensive kind of RAM.

What is DDR & SDRAM?

Double Data Rate (DDR) Synchronous Dynamic Random-Access Memory (SDRAM), officially abbreviated as DDR SDRAM, is a DOUBLE DATA RATE (DDR), SYNCHRONOUS DYNAMIC RANDOM-ACCESS MEMORY (SDRAM) class of memory integrated circuits used in computers. 

RAM SPEED REALLY MATTER?

RAM frequency is measured in MHz and usually immediately follows the DDR version in the RAM specification. For example, 8GB DDR4-2400 RAM is running at a frequency of 2400MHz. This is why though higher frequency RAM is technically faster.