Memory

Memory

Each different device will have different hardware, software and memory capabilities and restrictions. When designing a program for a certain device, for example a smart phone, research is crucial into the memory storage of the device, and how its interface relates to a specific browser.

Volatile Memory: Memory that you will lose once the device is powered down.

Non-volatile Memory: Memory that retains data once the power is shut off. Read only memories are the largest of these types.

More and more, browsers are starting to use non-volatile memory spaces to prevent annoying situations, for example, having to re-input user data upon a page refresh.

Random Access Memory (RAM)

Dynamic:

Data will leak even if power is on.
Based on capacitors.
Data must be refreshed about 1000 times a second.

Static (USB stick):

Will retain power as long as there is power.
Based on transistors.
Faster than DRAM but costs more.

Cache:

Fastest form of SRAM and also most expensive. Mainly utilised for holding most recent data.

Characteristics of RAM:

Capacity - The number of bytes that can be stored.
Speed - How quickly the data can be sent to the computer
Bandwidth - The rate at which the data can be sent to the computer
Technology - Typically DDR/DDR2/DDR3 soon to be entering the DDR4, as
the silicone is becoming smaller the voltage is also decreasing along the Buses.

When talking specifications, 50GB - the 'B' refers to eight bytes where as a specification of 100Mbps the 'b' refers to a byte.

All American standards are stated under IEEE. European standards are provided by ISO standards.