Essay On Primary Memory

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4.0 Primary Memory
There are two types of primary memory which are Random-Access Memory (RAM) and Read-Only Memory (ROM).
4.1 RAM Figure 4 : RAM
RAM is a type of computer data storage. RAM devices are used in computer systems as the main memory. RAM is considered volatile memory, which means that data stored in it is lost when we switch off the computer or if there is a power failure. So RAM is used by the central processing unit (CPU) when a computer is running to store information that needs to be used very quickly, but it does not store any information permanently. A RAM device makes is possible to access data in random order, which makes it very fast to find a specific piece of information. Certain other types of storage are not random-access. Access time in RAM is independent of the address that is each storage location inside the memory is as easy to reach as other locations and takes the same amount of time. Data in the RAM can be
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But, SRAM is faster than in comparison to DRAM. However, DRAM is smaller as well as less expensive per bit. While, the cycle time of SRAM is greater than DRAM and DRAM has more capacity than SRAM. DRAM is used as the main memory, whereas on-chip caches are usually SRAMs. Furthermore, DRAM supports access times of about 60 nanoseconds, SRAM can give access times as low as 10 nanoseconds. Despite SRAM being faster, it's not as commonly used as DRAM because it's more expensive. The simple structure of DRAM in comparison with SRAM also permits more data storage on the former. Thus, DRAM is often used for the computer’s main memory, and is actually the more common RAM found in PCs. DRAM advantage over SRAM is its structural simplicity that only one transistor calls MOSFET gates and a capacitor to store a bit as a charge are required per bit, compared to six transistors in SRAM. This allows DRAM to reach very high

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