When did the Hard Drive Companies forget how to count?

It seems that the hard drive companies have forgotten how to count or more to the point they think that we have forgotten how to calculate space. They think by manipulating the number base from a power of 2 to a base of 10 to make it look like you’re getting more space on the unit, however in actuality you’re getting less space on an average for example out of a 3 TB hard drive it will format to 2.72 TB, a 4 TB will format to 3.36 TB a 5 TB will format to a 4.54 TB and a 6 TB will format to a 5.45 TB hard drive you are losing about 500+ GB worth of space because of the way they have programed the chips on the drive. This to me is a lot of space that you paid for that you’re not getting, plus your being lied to by the companies when they say it’s a 6 TB hard drive and you get it formatted you find out it’s a 5.45 TB.

This was not always true, in the early 2000’s and before, the hard drive space was actually calculated correctly and always after formatting it was at least the advertised amount or greater.

Now it is always less, and I have heard companies blaming it on windows operating system as the problem this is an inaccurate statement and they need to own up to their doings. Which brings us to the next question.

Why have they done this should be the next question on everyone’s mind. I guarantee it is not by accident or even an over site on their part. It is deliberate, calculated action and here is why;

By changing their base from a power of 2 to a base of 10, they say it is better on you (the consumer), it makes it easier for you to understand. I don’t know about you, but I don’t like being called stupid. Most people who build and buy computer parts knows what they are doing and understands how hard drive space is and should be calculated. Making a claim in this fashion is an insult to our intelligence and is simply a ploy to force you to buy more product to get the amount of space in your project you’re looking for. At some point, most users have come across a situation where the capacity of a drive or disc isn't as large as advertised. Many times, this is a rude awakening for the consumer. This article examines how manufacturers rate the capacity of storage devices such as hard drives, solid state drives, DVDs and Blu-ray discs compared to their actual size.

Bits, Bytes, and Prefixes

All computer data is stored in a binary format as either a one or zero. Eight of these bits together form the most commonly referred-to item in computing, the byte. The various amounts of storage capacity are defined by a prefix that represents a specific amount, like the metric prefixes. Since all computers are based on binary math, these prefixes represent base 2 amounts. Each level is an increment of 2 to the 10th power or 1,024. The common prefixes are as follows:

• Kilobyte (KB) = 1,024 bytes
• Megabyte (MB) = 1,024 kilobytes or 1,048,576 bytes
• Gigabyte (GB) = 1,024 megabytes or 1,073,741,824 bytes
• Terabyte (TB) = 1,024 gigabytes or 1,099,511,627,776 bytes

This is important information because when a computer operating system or program reports the available space on a drive, it is going to report the overall total of available bytes or reference them by one of the prefixes. So, an OS that reports a total space of 70.4 GB has around 75,591,424,409 bytes of storage space.

Advertised vs. Actual

 Hard Drive Formatted Size that is they advertised as 1000 MB = 1 GB; and that reality is 1024 MB = 1 GB.

So, the ratio of the advertised over reality is 1000/1024= 97.7 percent of what it should be, you lose 2.3% as you go up the percentage gets bigger and bigger.

So, after formatting do not expect your capacity to be realistically over this percentage.

Since consumers don't think in base 2 mathematics, manufacturers decided to rate most drive capacities based on the standard base 10 numbers we are all familiar with. Therefore, one gigabyte equals one billion bytes, while one terabyte equals one trillion bytes. This approximation was not much of a problem back when we used the kilobyte, but each level of increase in the prefix also increases the total discrepancy of the actual space compared to the advertised space.

Here is a quick reference to show the amount that the actual values differ compared to the advertised for each common referenced value:

• Megabyte difference = 48,576 bytes
• Gigabyte difference = 73,741,824 bytes
• Terabyte difference = 99,511,627,776 bytes

Based on this, for each gigabyte that a drive manufacturer claims, it is over-reporting the amount of disk space by 73,741,824 bytes or roughly 70.3 MB of disk space. So, if a manufacturer advertises an 80 GB (80 billion bytes) hard drive, the actual disk space is around 74.5 GB of space, roughly 7 percent less than what is advertised.

This isn't true for all the drives and storage media on the market. This is where consumers must be careful. Most hard drives are reported based on the advertised values where a gigabyte is one billion bytes. On the other hand, most flash media storage is based on the actual memory amounts. So, a 512 MB memory card has exactly 512 MB of data capacity. The industry has been changing on this as well. For instance, an SSD may be listed as a 256 GB model but have just 240 GB of space. SSD makers set aside extra room for dead cells and for binary vs. decimal difference.

Formatted vs. Unformatted

For any type of storage device to be functional, there must be some method for the computer to know which bits stored on it relate to the specific files. This is where the formatting of a drive comes in. The types of drive formats can vary depending on the computer but some of the more common ones are FAT16, FAT32 and NTFS. In each of these formatting schemes, a portion of the storage space is allocated so that the data on the drive can be cataloged enabling the computer or another device to properly read and write the data to the drive.

This means that when a drive is formatted, the functional storage space of the drive is less than its unformatted capacity. The amount by which space is reduced varies depending upon the type of formatting used for the drive and the amount and size of the various files on the system. Since it does vary, it is impossible for the manufacturers to quote the formatted size. This problem is more frequently encountered with flash media storage than larger capacity hard drives.

Read the Specs

It is important when you purchase a computer, hard drive or even flash memory to know how to read the specifications properly. Typically, manufacturers have a footnote in the device specifications to show how it is rated. This can help the consumer make a more informed decision.