Mobile phone memory explained, types of mobile phone memory
Mobile phones have different kinds of memory in it for different reasons. There is RAM (Random Access Memory) and ROM (Read only Memory). We explain what RAM and ROM mean. Then there are the different mobile phone memory card types and that also is explained below.
Mobile phone RAM and ROM
The two types of memory used in a mobile smart phone are as follows:
Random Access Memory or RAM in a smartphone
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.
Read Only Memory or ROM in Smartphones
The memory chip on which the phone's Operating System OS is stored is called a ROM (read only memory). When the OS like iOS Android or Windows, is updated these chips get rewritten even though they are called Read Only. Only system updates can rewrite into those chips and it is not possible for the user to rewrite these OS ROM memory chips. The ROM chips used for storage of the phone OS are usually only about 512 MB.
Best micro SD cards for mobile smart phones
The best micro SD card available now is the Class 10 micro SD card which is able to write at a speed of 10 MB/second. The external SD card memory operates much slower than the phone’s internal memory, so it is always best to have your apps in the phones internal memory. Also while taking photos and videos, it is better to use the phones internal memory and as soon as possible to transfer the photos and Videos to the external microSD card. This way the internal memory should be made free for faster operation of the camera phone.