Cell Phone Basics explained

Smart Cell phone memory types, internal memory in cell phone

Cell phones have different types of memory in it for different applications. We explain what is the use of RAM and ROM in mobile phones and what is the difference between RAM and ROM

What is RAM in cell phone, how much RAM do I need for my phone

The use of RAM in mobile phone speeds up the functioning of all mobile cell phones. How much RAM do I need for my phone? The short and simple answer is get as much as you can, because the more the RAM the faster the phone applications will execute. 2 GB of RAM will be fine for most applications, but if you do a lot of gaming then try to get the maximum possible, because to have fast responsive gaming experience you need a lot of RAM. Why RAM is so important for faster operation of your phone will be clear when you read the following:

RAM or ‘Random Access Memory’ in a mobile phone is a memory that is temporary but is quickly accessible to the phone’s processor. 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 where each Mega byte is equal to a million bytes – in short a Giga byte or GB is a billion 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 powering ‘off’ and ‘on’. Thus the memory of a RAM is very volatile and dynamic, and so RAM is referred to as having a ‘Volatile Memory’ and being dynamic, RAM is commonly called as ‘Dynamic Random Access Memory’ or ‘DRAM’.

The internal memory of mobile cell phones are slower to access than the RAM and so the RAM gets the required memory from the hard disk loaded on to it just before it is required by the processor. The timing of the loading and what is required to be loaded is all done by the Operating System, like iOS or Android. With an efficient OS (Operating System) you can have fast responsive phone without having a lot of RAM.

The most important factors affecting how fast the RAM speed are the clock speed of the RAM, the type of RAM and the number of channels the RAM has. For cell phones the clock speeds of RAM are kept at moderate rates of 300 to 500 MHz to save on power usage.

Cell phones do not have a motherboard as in PCs, but instead use a ‘System on Chip’ or SoC which in a single chip combines the functions of the main processor, graphics processor and RAM and are designed to be small and compact to fit inside a smartphone. While the RAM in laptops and computers are the latest DDR3 SDRAM (double data rate third generation synchronous dynamic random access memory) smart phones makes use of LPDDR2 (low-power double data rate 2nd generation) RAM.

Read Only Memory (ROM) in Cell Phones

The internal memory storage in cell phones are usually divided into more than one memory chip. The clock speeds of these internal chips vary, because the faster a memory chip is, the more expensive it is. So to save on costs smartphone manufacturers have the fastest memory chips for the main OS (Operating System) like iOS or Android. The memory chip on which the phone OS is stored is called a ROM (read only memory) even though these chips are rewritten when the OS is updated. The reason for this is that only a system update can rewrite into those chips and it is not accessible to the user. These ROM chips for storage of the phone OS are usually only about 512 MB.

Difference between phone memory and internal memory

The difference between phone memory and internal memory is that what people casually refer to as the ‘Phone memory’ in a cell phone is the random access memory or ‘RAM’ available on the phone. Whereas internal memory in a mobile phone is for use in storage of Apps and the users data.

The internal memory of phones are not as fast as the RAM or the ROM memory chip used for the OS storage, but they are much faster than the user replaceable SD card external memory. Many leading phones like iPhones do not have the facility of an external storage, but have plenty of internal storage from 16 upto a maximum of 128 GB, which is more than adequate for normal use. HD videos and Photos are the most memory consuming activity for a mobile phone. So for example, per hour of 1080 HD video uses a maximum of 12 GB of memory space per hour, so a 16 GB Apple cell phone without memory card should be more than adequate for someone who will not take more than an hour of HD video before moving the video file to another storage device like his laptop or external hard drive.

Difference between SD card and phone storage

The main difference between phone storage and external SD card memory is that the phone storage internal memory is very fast in saving and retrieving info when compared to the external SD card memory. The SD cards are usually slower to read and write than phone storage which is an internal memory chip. The fastest micro SD card available is the Class 10 micro SD card is only 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 move transfer the photos and Videos to the external microSD card. This way the camera performs better, and you can free up the internal memory whenever you get a chance.

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