Why Is My Hard Drive Smaller than Advertised?
An Explanation and Tips on what company gives you more space.

Ok, so you buy a new hard drive and install it. The box says that it is 120 GB, and it shows up as 111GB. Where did your other 9GB go? Actually, you are only missing about 10MB, because the hard drive companies measure their hard drives in 1000MB GBs, while Windows sees 1024MB as a GB. So Hard Drive companies base their Gigabyte on Decimal and Windows on Binary.

Here is a run down of some hard drives and their Windows formatted sizes.

120GB Western Digital 7200RPM 8mb Cache IDE: 111GB or 120,031,477,760 bytes. Rounded to 120GB, the advertised size.

120GB Maxtor 7200RPM 8mb Cache IDE: 114GB or 122,934,034,432 bytes. Rounded to 123GB. That's 3 more GB.

120GB Seagate 7200RPM 8mb Cache IDE: 111GB or 119,990,349,824 bytes. You can round that to 120GB.

So between the three popular manufacturers, though they all give you the amount advertised, in space, Maxtor comes out on top because they give you extra, while Seagate and Western Digital try to hit right at 120GB. Maxtor wants to go a little bit extra, which doesn't hurt at all. I have no preference which hard drive to buy. I don't think that any hard drive manufacturer is necessarily better than the other, some people hate one kind of drive because one or two failed on them, I have seen people complaining about every hard drive manufacturer, to keep them from failing, keep them cool, don't be mean to them and they will last longer. A hard drive will die, that's life, just back up your important stuff on CDs, DVDs, or other media. Me, when choosing which hard drive between Seagate, Maxtor, and Western Digital, I choose the cheapest alternative. When choosing between 2 stores both offering a hard drive for the same price and the same rebate amounts, I probably choose the one that is closer or gives me the rebate form with my receipts instead of a whole booklet like some stores. **Cough** Office Max **Cough** (Update: Office Max no longer does the rebate booklet so now you can choose on distance when prices are the same) :)

I don't have the time or resources to gather up data from 100 hard drives of each type and doing the average, so these numbers may not be typical, since it is nearly impossible for manufacturers to hit exactly on the mark every time, count these as rough estimates. Also, I guess that hard drives also get smaller when they are formatted.

UPDATE: Many of these companies have been involved in class action lawsuits so check for settlements, I know Western Digital gave away some kind of software, Lexar gave huge store discounts, and I expect more to come.

BACK TO ARTICLES