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Memory

Memory is typically a piece of hardware intended to store data or instructions, it can be categorised into three categories:

  • Volatile where if power is lost, so is the data.
  • Non-Volatile where if the power is lost, the data will remain.
  • Read-Only where the data can only be read from, not written to.

Read Only Memory (ROM)

ROM is a form of memory of which is written to during manufacture and not intended to be written to again (or at least modified by the consumer). It is typically used by motherboard manufacturers to store the BIOS.

Random Access Memory (RAM)

RAM is a form of memory of which is used for the temporary storage of data, such as computer programs or files. RAM modules typically have a speed measured in Megahertz - so no where near the Gigahertz that the CPU runs at. To prevent this becoming a bottleneck, CPUs have a hardware cache that they use to minimise the amount of lengthy RAM operations they do.

Should all of the installed RAM modules in a computer all have run out of capacity, Virtual Memory will begin to be used - only temporary though.

Virtual Memory

Virtual Memory is a form of memory that stores data on the computer's secondary storage when the installed RAM modules have run out of capacity. It is much slower than RAM, so the avoidance of it is rather important for running a performant machine.

If a machine is constantly using Virtual Memory, looking at increasing the RAM capacity would be in order.

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