Answer to Question #64709 in C# for Kamlakar

Question

What is cache memory? How is it different from RAM and ROM?

Answer 1

RAM, or Random Access Memory, is responsible for holding raw forms of data that are either waiting to be processed or stored to disk, as well as running the installed operating system. The major disadvantage RAM has is that once a device is shut down, all unwritten data is lost.

ROM, or Read Only Memory, cannot be changed. Unlike RAM, it is permanent data that is used to instruct a device what processes to use when starting up. ROM allows a CPU to make use of installed hardware, disk drives and other system critical components every time it is booted up, as RAM is only usable when a machine is powered.

Cache gives a CPU fast access to resources by anticipating how much RAM is needed for a task, before allocating that amount for the CPU to use. This means the CPU does not have to draw from the RAM directly, which would slow processes down. Cache memory is a bit like RAM, except it's built right inside a processor and is even faster than RAM. It's used by the processor to avoid having to slow down to the speed of the RAM all the time. Like RAM, it is also volatile. Cache memory is usually quite low-capacity (a few megabytes), so we still need RAM in order to avoid constantly accessing things from slow storage media.