Yes, I am pleased to learn of Hitachi’s plan to release probably-functional “one terabyte” hard drives Real Soon Now. They’ll probably work fine, the price is good, it’s like Bigfoot or Jesus. Huzzah.
This is, however, a good time to mention that now that consumer hard drives are nudging the “1Tb barrier”, the capacity rip-off factor is about to become worse by a factor of 1.024. Again.
As I and others have written many times before, storage manufacturers are, almost without exception, in love with specifying their devices as if a kilobyte is 1000 bytes, a megabyte 1000 kilobytes, a gigabyte 1000 megabytes, and (now) a terabyte 1000 gigabytes.
According to the standard SI prefixes, this is exactly true. There are one thousand grams in a kilogram, after all.
In computer usage, though, those SI prefixes are perverted to refer to powers of two, not ten, despite the so-far-unsuccessful effort of the standards organisations to get everybody to call the computer capacities “kibibyte”, “mebibyte” and so on.
So a real kilobyte, as used by every desktop computer operating system, contains two to the power of ten, 2^10, 1024, bytes. A real megabyte contains 2^20, 1,048,576, bytes. A real gigabyte contains 2^30, 1,073,741,824, bytes. A real terabyte contains 2^40, 1,099,511,627,776, bytes.
As you can see, the difference between the powers of ten and the powers of two - the rip-off factor, in other words - gets worse and worse as capacities rise. Once you get to the terabyte level, the factor is very nearly 1.1.
There can be a further loss of capacity from the space taken up by formatting data - the metaphorical painting of the lines on the parking lot. But that varies with the filesystem you use, and the actual raw capacity you get from a drive with sticker capacity X varies, too.
That capacity is never high enough to cancel out the 1000/1024 rip-off factor, but it often is enough to account for the space taken up by formatting. The “320Gb” Western Digital drives in my current computer do indeed format to 298Gb, exactly what you get if you divide 320 by 1.024 three times. That’s thanks to an extra 67-odd megabytes of space, which cancels out the formatting losses. They’re still nowhere near 320 real formatted gigabytes, though.
So even if the new “one terabyte” drives are similarly generous, you can only expect them to format to
909 - maybe 910 - gigabytes 0.91 real terabytes, which is 931 real gigabytes.
So, OK, maybe not technically ninety gigs down the toilet. Maybe only 69, depending on which way you look at it.
Either way, that’s a lot of $US5000 18 megabyte Winchesters. And there are still plenty of hard drives on the retail shelves that don’t hold as much as this new one will rip you off for.
So, until someone starts selling a “1.1Tb” or larger drive, the true 1Tb barrier for single drives will not be broken.
The mismatch, of course, may be getting worse, but it arguably matters less and less, as the price per megabyte of hard drives continues to fall.
But that doesn’t mean that people in the year 2020, or whenever, won’t feel fleeced when their new “1Pb” drive only formats to a lousy
888 909 terabytes.