Computer Systems 2 Memory Flashcards
What is primary memory?
Primary memory is built inside the computer. As a result, data can be read from and written to primary memory extremely quickly. This gives the processor fast access to the data and instructions that the primary memory holds.
What is ram?
RAM is temporary memory. It holds data and instructions of the program currently being executed.
The more RAM a computer has, the more data and programs it can hold simultaneously.
RAM can also be upgraded easily, unlike other types of primary memory
What is the BIOS?
The BIOS runs as soon as the computer is switched on. It checks that the hardware is functioning correctly, then runs a second program known as the bootup or bootstrap program that loads the computer’s operating system from the hard drive into the RAM. The BIOS is always needed so it is stored in ROM.
What is ROM?
ROM’s contents remain stored regardless of whether the computer is powered on or off. A typical use of ROM is the computer’s BIOS (Basic Input/Output System) settings.
What is virtual memory?
Virtual memory is used when the computer has no more available RAM. There are times when the amount of RAM needed to hold all running programs and data is greater than the amount of RAM available to the computer. When this happens, part of the computer’s secondary storage, such as the hard disk, can be used to store data temporarily.
What is swapping (in terms of virtual memory)?
Swapping is the process of moving data from one running application out of RAM and into virtual memory. Data that is in RAM and not currently being used to be transferred to the hard disk. This frees up room in RAM for other programs and data. When the data on the hard disk is needed again, any other unused data is transferred to the hard disk before the original data is transferred back to RAM.
Using virtual memory makes a computer run slower, as the processor has to wait while data is swapped between hard disk and RAM.
What is cache memory?
Cache memory is a type of high-speed random access memory (RAM) which is built into the processor.
It’s faster than RAM. As a result, cache memory is used to temporarily hold data and instructions that the processor is likely to reuse. This allows for faster processing as the processor does not have to wait for the data and instructions to be fetched from RAM.
However, because of its high-speed performance, cache memory is more expensive to build than RAM. Therefore, cache memory tends to be very small in size.
What is L1 cache?
● L1 cache has extremely fast transfer rates, but is very small in size. The processor uses L1 cache to hold the most frequently used instructions and data.
What is L2 cache?
● L2 cache is bigger in capacity than L1 cache, but slower in speed. It is used to hold data and instructions that are needed less frequently.
What is secondary storage?
Secondary storage is non-volatile, long-term storage. It is used to keep programs and data indefinitely. Without secondary storage all programs and data would be lost the moment the computer is switched off.
● magnetic storage devices; hard disk drives (HDD)
● solid state storage devices, solid state drives (SSD) and universal serial bus (USB) memory sticks
● optical storage devices, such as CD, DVD and Blu-ray discs
