RAM (Random Access Memory)
RAM stands for Random Access Memory. It is temporary memory. In Random Access Memory data and information are not stored permanently.
When the computer is turned on, it uses Random Access Memory to write and read data and programs. When the computer is turned off, all programs and data are erased from the RAM. RAM is therefore, also called volatile memory. It is like a whiteboard on which information can be written, read, cleared and rewritten. We can read, write and delete information from RAM. The technology, which is nowadays used for RAM, is CMOS (Complementary Metal Oxide Semiconductor). This memory consists of small blank chips. Blank memory chips are fixed on a, single inline memory modules (SIMMs). Basically SIMM is a circuit board, which can hold a group of memory chips. Microprocessor fetches data from RAM and executes the instructions provided by the user of a computer.
RAM is further divided into the following categories:
- DRAM (Dynamic RAM)
DRAM stands for Dynamic Random Access Memory. Like a RAM chip, a DRAM chip stores data in the form of electric signals having ON/OFF states. It is a popular type of RAM and is mostly used in computers. DRAM is refreshed many times in a second that is way it is slow. During the refreshing process, the processor of the computer cannot read or write data in the DRAM. However it is cheaper, easily available and requires less power. The refreshing process of the DRAM decreases the processing speed of the computer. This type of memory was used in old microcomputers.
- SRAM (Static RAM)
SRAM stands for Static Random Access Memory. The SRAM chip requires more power and compared to the DRAM. Static RAM is not popular but it is faster than DRAM because it does not have to refresh many times in a second. It is expensive and requires more space and power than DRAM. In large computers and also in microcomputers, the SRAM is used. The SRAM chip increases the processing speed of the computer. It is about 10 times faster than the DRAM.
RAM AND CPU INTERACTION
The CPU processes (performs instructions on things, such as adding) stuff in memory. RAM is just part of the memory. So when you are processing lots of data, that data (or maybe large portions of it) will likely get loaded into RAM so it is ready for the CPU, this is to speed up the things because RAM is faster to access than storage devices. So CPU usage and RAM can often correlate.
A basic example might be an image editing program. I load up my 20MB jpeg, the program reads the entire image, and the OS keeps that in RAM for you (all working memory looks the same to the program, the OS decides if it goes to the page/swap file on disk or RAM). So the image is in RAM waiting to be processed, but I go for tea. CPU cannot do anything with image in that time. I come back, add some bubbles to the image, and the CPU goes to 100% and even more memory gets used because it keeps the preprocessed image in memory.
You can Watch this video to learn more About RAM and its Working.