What is a dynamic memory with random access?
Dynamic memory with random access or DRAM is the most common type of computer memory. It is particularly useful for computers, because in a small physical space it can contain a lot of data. Usually, however, does not retain data when its power is off, which means that it is not suitable for permanent storage.
Memory with random access simply refers to memory where every piece of data can be accessed almost immediately. This is, unlike storage media, such as cassette tapes, where data can only be accessed in a fixed sequence. The "dynamic" element of DRAM is that its power must be constantly restored to work. This distinguishes from static memory of random access or SRAM. With static random access memory, this is done through an electric current that can be switched to two different directions. With the dynamic memory of random access, this IS done by a number of cells that are either full of electrons or empty. All cells, however, automatically discharge almost immediately,Therefore, they need to be constantly supplemented.
Most computers use two types of memory together. Generally, dynamic memory with random access is used in larger capacities because it is much more efficient space and therefore cheaper. A static memory with random access is usually used for cache, which is faster for access, but less efficiently efficient. This involves storing data that the computer is likely to need during operation, which reduces the number of times the computer has to access a slower DRAM.
Because the dynamic random access memory needs power supply to continue to refill cells, it usually cannot store data as soon as the power stops, for example when the computer is turned off. This differs from a form of memory such as Flash, used for memory cards and solid states. This is one of the reasons why DRAM is much cheaper notŽ Flash memory card of the same capacity.
The way the dynamic memory of accidental access works ensures that it will continue to hold data if the power source allows it to add cells. On the contrary, it does not work: there is no warranty that the power cutting will delete memory. Although it is extremely difficult to do in practice, there are several theories about how to access the computer's memory that has been turned off, for example by freezing the memory chip and switching to another machine. This has questioned the reliability of some safety measures that encrypt the hard disk and store the encryption key in the DRAM.