Bit is the basic unit of information used in computing. A single bit can represent a value that is either true or false – one or zero.
For a long time that was all that was needed, but with recent new technologies the situation has changed.
As the geekier ones of us already know, the latest innovation from the computer equipment manufacturers is a bit that can vary in weight. The technology is called VWBS, i.e. Variable-Weight Bit Storage. Previously all the bits in a single hard disk had the same weight. As the manufacturers were able to make lighter bits, the hard disks got physically smaller, and the amount of data that a single hard disk was able to store got larger.
With VWBS, the exact amount of bits that a hard disk is able to store isn’t a constant anymore. Instead the weight of each bit stored affects the total amount of bits that the hard disk can hold. That’s why a new unit of memory capacity was adopted: the grambit,
gb is not to be mixed up with
GB (gigabyte), which is often used to measure the capacity of a hard disk without VWBS technology.
Let’s say we have a
100 gb hard disk. If we use
0.10 ng (nanogram) bits, we’re able to store
100 gb/(0.10 ng) = 1 000 Gb (gigabit) of information to it. But if we use the lighter
0.08 ng bits, we’re able to store
100 gb/(0.08 ng) = 1 250 Gb.
1 000 Gb = 125 GB and
1 250 Gb ≈ 156 GB.
If we have stored
500 Gb of
0.08 ng bits to a
100 gb hard disk, the remaining capacity is
100 gb − (500 Gb · 0.08 ng) = 100 gb − 40 gb = 60 gb.
© 2011 Johan Kiviniemi
The image of a giraffe is from Wikimedia Commons