Random Access Memory
Random Access Memory or RAM in a mobile phone is very important and the higher the RAM in a cell phone, the faster the mobile cell phone will operate.
RAM is a very fast responding memory that can be quickly erased and new data written on it. All applications to be executed on a phone is first loaded on to the RAM from the main storage memory of the phone.
The main memory of a phone is slow and it cannot execute programs on the phone fast enough. So the phones Operating System, like iOS or Android controls the RAM and decides on the timing of loading into the RAM of what is required in the next few milli-seconds while a phones App is being executed, and loads those programs from the slow loading memory into the fast RAM ready to execute when required. As soon as the RAM executes that part of the App, fresh memory required for the next few milliseconds are loaded on to the RAM and the old executed portions are erased from the RAM.
The RAM is made up of millions of capacitors each capable of holding one ‘bit’ of information. That means in a RAM of 1 GB there should be at least 1,000,000,000 capacitors since a Giga byte = 1000 Mega bytes. The Capacitors in the RAM lose its charge as soon as it is powered off, so all of the Memory in a RAM can be removed and new memory loaded in the RAM in a fraction of a millisecond just by switching it ‘off’ and ‘on’.
Since the memory of a RAM is very volatile and dynamic, RAM is referred to as having a ‘Volatile Memory’ and being dynamic, and often referred to as ‘Dynamic Random Access Memory’ or ‘DRAM’. The speed of the RAM is known as 'clock speed'. For cell phones the clock speeds of RAM are kept at moderate rates of 300 to 500 MHz to save on power usage. The RAM in smart phones are a type known as LPDDR2 (low-power double data rate 2nd generation) RAM. In a laptop computer faster DDR3 SDRAM (double data rate third generation synchronous dynamic random access memory) are used, but they consume much more power and so cannot be used in smartphones.
