LOL thats not just sony man every HDD is that way.
It turns out that a decimal gigabyte is approximately 93% the size of a binary gigabyte, so if your hard drive is 40 decimal gigabytes, your operating system will report that it is approximately:
40 decimal gigabytes * 93% = 40 * 0.93 = 37.2 binary gigabytes
Which is exactly the hard disk capacity that is reported by operating systems such as Windows XP. Likewise, a 1 decimal terabyte hard drive is 1000 decimal gigabytes. Windows will report that hard disk’s capacity as approximately:
1000 decimal gigabytes * 93% = 1000 * 0.93 = 930 binary gigabytes (this is very close to what Windows reports; however, the multiplication factor isn’t exactly 0.93, as we’ll see below)
So simply put, when you purchase a digital storage medium, you can expect your operating system to identify it as being about 93% the size that you expect it to be. You’re not being ripped off; it’s just that the word “gigabyte” is used to mean two different things.