According to Wikipedia:
The use of gigabyte may be ambiguous. Hard disk capacities as described and marketed by drive manufacturers use the standard metric definition of the gigabyte. Therefore, one gigabyte is 1 000 000 000 bytes(GB).
This is true even for phone manufacturers, in fact just as rjknight pointed out, The RAM marketing strategy is similar to the "hard drive maker conspiracy" story is driven by the fact that manufacturers have no real incentive to switch to binary prefixes, because that would make their drives (RAM in this case) look "smaller".
AFAICT, using the mebibyte (MiB), gibibyte (GiB) and so on, is a more accurate way of presenting the volume of data stored in these quantities.
The gibibyte or binary gigabyte is a multiple of the unit byte for digital information . The binary prefix gibi means 2^30 , therefore one gibibyte is equal to 1 073 741 824 bytes = 1024 mebibytes .
These other binary prefixes (kibi, mebi, tebi, etc.) were introduced in an attempt to reduce such confusion, but these prefixes have yet to see widespread adoption.
In PC 2GB of ram refers to gibibytes, not gigabytes. RAM comes in allocation in powers of 2 due to architecture. Memory addressing is done in binary form, this implies it is going to be a power of two.
So, since writing memory addresses in binary always results in a binary number, RAM developers have (almost) always stuck to creating RAM in units of powers of 2, combining individual chips which are (almost) always combining to powers of 2.
Here is another explanation:
RAM is addressable by an index called an address . The most efficient way to construct this address is as a binary number which corresponds to the physical area on the chip where the byte or word of memory is accessed from. As a matter of efficiency its expensive to check this address for validity (does the address really correspond to a real address?) for every access. The only way to restrict the address range without having to check the value is to allow for every possible combination of bits, but set the exact number of valid bits that are supported for the RAM chip. But that means your range has to be a power of 2.
RAM that is used in smartphones is technically DRAM, with the D standing for dynamic. The structure of DRAM is such that each capacitor on the RAM board stores a bit, and the capacitors leak charge and require constant xe2x80x9crefreshingxe2x80x9d; thus the xe2x80x9cdynamicxe2x80x9d nature of the RAM. It also means that the contents of the DRAM module can be changed quickly and easily to store different files.
And as expected, the exact number of bytes in a DRAM module is always an integral power of two.
This is is more like a business idea, that takes advantage of confusion regarding the common usage of "gigabyte" instead of "gibibytes" much like ISPs advertise 8Mbps (= 1MBps) as 8MBps, so it needs awareness from end users or customers.
It seems most manufacturers hide under metric system or SI units to "advertise" to the unsuspecting consumers, although in real terms the say what they don't mean.
- Why is 1 GB equal to 10^9 bytes instead of 2^30?
- Why does RAM come in specific sizes (256, 512, 1024, 2048, etc)
- About Random Access Memory (RAM)