- RAM (Random Access Memory) is the internal memory of the CPU for storing data, program, and program result. It is a read/write memory which stores data until the machine is working. As soon as the machine is switched off, data is erased.
- RAM is volatile, i.e. data stored in it is lost when we switch off the computer or if there is a power failure. Hence, a backup Uninterruptible Power System (UPS) is often used with computers. RAM is small, both in terms of its physical size and in the amount of data it can hold.
Types of RAM-
RAM is of two types −
- Static RAM (SRAM)
- Dynamic RAM (DRAM)
1. Static RAM-
The word static indicates that the memory retains its contents as long as power is being supplied. However, data is lost when the power gets down due to volatile nature.
There is extra space in the matrix, hence SRAM uses more chips than DRAM for the same amount of storage space, making the manufacturing costs higher. SRAM is thus used as cache memory and has very fast access.
CHARACTERISTIC OF STATIC RAM
- Long life
- No need to refresh
- Faster
- Used as cache memory
- Large size
- Expensive
- High power consumption
Types of SRAM-
Basically Static Random Access Memory Categories into four parts-
- Non-volatile SRAM
- Special SRAM
- Asynchronous SRAM
- Synchronous SRAM
2.Dynamic RAM-
DRAM, unlike SRAM, must be continually refreshed in order to maintain the data. This is done by placing the memory on a refresh circuit that rewrites the data several hundred times per second.
DRAM is used for most system memory as it is cheap and small. All DRAMs are made up of memory cells, which are composed of one capacitor and one transistor.
CHARACTERISTICS OF DYNAMIC RAM
- Short data lifetime
- Needs to be refreshed continuously
- Slower as compared to SRAM
- Used as RAM
- Smaller in size
- Less expensive
- Less power consumption
Types of DRAM-
Basically Dynamic Random Access Memory Categories into four parts-
- SDRAM (Synchronous Dynamic RAM)
- RDRAM (Rambus Dynamic RAM)
- DDRAM (Double Data Dynamic RAM)