RAM (random access memory) is the memory that the computercan use ‘randomly’, this is the memory that is kept available for programs touse – the memory available is measured in gigabytes (GB) and speed is measuredin megahertz. This means the more RAM a computer has, the faster it willoperate and will be able to operate more software at the same time, this memoryis known as volatile memory as it is lost when the system is powered off, whichis why we save our games/work and they go to storage – the hard drive. UnlikeROM (read only memory), which cannot be lost or altered. ROM does basic,necessary functions such as booting up a computer system as it contains theBIOS. The BIOS on the ROM chip is a collection of software utilities that bootsup the system every time it is turned on while checking the hardwareconfiguration against the configuration data called the POST process (power onself-test). There are a number of different types of RAM; dynamic RAM(DRAM) is memory that stores bits of data in cells consisting of capacitors andtransistors, which millions of the cells make up the RAM – the memory must berepeatedly refreshed, or it will forget the data it was holding, this processtakes more time and slows down the memory.
On the other hand, static RAM (SRAM)is made up of 4/6 transistors plus wiring and retains its data in its memory aslong as the computer has power, so it does not need to be refreshed, whichmakes it faster than DRAM but also more expensive. Rambusdynamic RAM uses a RAM controller and bus connected directly to the processorand other devices that require it and provides a consistent 1.6 GB per secondof memory bandwidth that runs at 800 MHz; this type of memory was useful inearlier gaming platforms like the N64. However, modern memory has usedvariations of these types to create faster, more efficient forms of RAM.Synchronous dynamic RAM SDRAM was a variation in the 1990s that allowed thememory’s responses to be synchronised to controls inputs in the data buses –this meant it could queue processes up whilst a process is being completed. Double date rate (DDR) was introduced in 2000 which allowedthe memory to transfer data on the falling as well as the rising edges of theclock signal so that it was continuous and doubled the transfer rate andallowed RAM to run at a lower clock rates to use fewer volts but still keep uphigher transfer speeds. The DDR versions of RAM have been upgraded into theirfourth version today by expanding on the existing idea, the DDR4 RAM allows upto twice as much GB (4-16 GB), doubled data rates, and a lower voltage requiredto run.
For examples of different RAM usage, the Samsung Galaxy S7 uses 4 GB ofDDR4 RAM, and Nintendo 3DS XL uses 128 MB of FCRAM (a type of SDRAM developedby Fujitsu and Toshiba). While the PS4 Pro uses GDDR5 8 GB RAM which is a typeof RAM that only works for graphics cards and desktop PCs can have as much RAMas the motherboard and OS can support but adding more than necessary does notmake a computer faster.