So it is the Holiday season and you decide to buy a nice computer with an 8 gigabyte hard drive and a 17 inch monitor.
Only to find when you measured the actual stats, you bought a 7.4 gigabyte hard drive and a 15 inch monitor.
What happened? Back in the early days of the PC. Companies started finding ways of artificially inflating their specifications. Unfortunately, these measures have become standard over the whole industry. What we really have is industry wide lying.
Lets start with monitors. TV sets have always been measured by the diagonal screen size. In the early days of TV, the sets were far larger than the screens. So it was only fair to measure them by the actual screens.
For whatever reason, the computer industry started measuring the plastic frame around the screen, this added a couple of inches to the actual screen size. A 14" screen is by TV standards, about a 12" screen. A 17" screen is usually a little smaller than 15".
Luckily someone sued (every once in a while lawyers prove worthwhile). Now all print advertisement includes a "viewable area" specification, though it is in a smaller type and hidden in fine print. If you want to know what kind of monitor you are buying, go by viewable area rather than the advertised statistic. ( Just a small bit of advice, also check the dot pitch of the monitor as well. The smaller the number the crisper the picture)
Kilobytes, Megabytes, and Gigabytes
Despite the metric names, these are not true metric measures. Everything in computer hardware is measured in powers of two rather than powers of ten. A kilobyte is not really 1000 bytes, but 1024 bytes. 1024 is equal to 2 to the 10th power. This is because computers think in base two (also known as binary) numbers. This makes it difficult for us who think in base ten (also known as decimal) numbers.
We try to make some easy conventions, though. A kilobyte is 210, a megabyte is 220, or a kilobyte squared, or 1,048,576. And, it follows that a gigabyte is 230, or a kilobyte cubed, which is 1,073,741,824.
Hard drives
The problem is that hard drive makers decided not to follow this convention. They stuck with traditional metric measures. So when you buy an 8 gig hard drive you are really getting a 7.4 gig hard drive. This is because 8,000,000,000 ÷ 1,073,741,824 = 7.45. This is yet another case of inflating the numbers by non-standard manipulation.
There are other mathematical lies in the computer industry. 32x speed CD ROM drives run an average of less than 24 speed. This is because 32 speed is only the fastest speed. The internal part of these drives only spin at 16 speed. Most of the data on a CD is in this 16 speed zone. Another lie involves the speed of the processor. The MHz of the CPU clock speed is not an accurate measure of actual performance. The bus speed and the internal L1 and L2 cache have a lot to do with it. With the right support hardware a 300 MHz processor can out perform a 400 MHz processor.
These are only the mathematical lies of the computer industry. I am not even touching all the factual lies like plug and play, free technical support, and a few other misnomers.