Aaarrrggghhh!!!Hitachi has just announced their new 1 terabyte hard drive. This is very exciting news because this continues to drive the cost of storage down. But, of course, there is an issue. In fact, this is really an old issue but because disk sizes are continuing to increase, we are starting to see the issue more and more.

When you plug in the 1 TB hard drive, your system shows that you only have 931.51 GB of disk space instead of the expected 1,024 GB a difference of 9.9%! The reason that you are getting less disk space than what was advertised is because of the definition of a terabyte (and a gigabyte, megabyte, kilobyte, etc. as well).

The true definition of a terabyte is 240 or 1,099,511,627,776 bytes. But, someone decided that it is easier math (and better marketing) to make a terabyte equal to 1012 or 1,000,000,000,000 bytes. Which would be fine except the computer systems understand the true definition of a terabyte and show you the information accordingly.

This has been going on for a very long time and we have even seen this in the days of megabyte sized hard drives. But, because the disks are getting to be so large, the lost storage space is starting to really become noticeable. The “terabyte” drive is “stealing” 92.6 GB (true calculation) of storage from every drive it delivers.

This will continue to occur in the foreseeable future. Here is a list of how much disk space you will be losing come the next few levels of disk space:

Unit Lost % Lost
terabyte 92.6 GB

9.05%
petabyte 114.5 TB

11.18%
exabyte 135.8 PB

13.26%
zettabyte 156.6 EB

15.30%
yottabyte 176.9 ZB

17.28%

Now, do I really think that the hard drive manufacturers are stealing from the consumers. No. It is simply a marketing and math thing. But, I do get calls from time to time with people asking why my new drive is showing less than it says on the box. It is just a matter of knowing.

Trackback link - http://www.dailycupoftech.com/2007/04/26/hitachis-new-terabyte-hard-drive-isnt/trackback/
Tim Fehlman