My hard drive Size is not correct ?

Asked By 0 points N/A Posted on -

Hello Friends.

I bought a new hard drive of size 160GB from the market.

The hard drive has 160GB printed  on it.  

But I have seen that  Windows XP disk management shows,  149.04 GB.

What is this?

Where is the remaining space?

Best Answer by Patrick b
Answered By 0 points N/A #125522

My hard drive Size is not correct ?


First of all you do not have to worry about the hard drive you just bought, as it is not defective in any way even with the missing capacity. In some instances the hard drive are already partitioned therefore, creating the missing amount of disk space, but with brand new hard drives, this missing amount of disk space is due to what is referred to as "Rounding".

Rounding is done by the manufacturers of advertising a product to be 160GB when in reality the disk space is much lower. Manufacturers perform Rounding because they assume that kilobytes (KB), megabytes ( MB), gigabytes (GB), and terabytes (TB) are something else from what they truly are and this leads to false advertising.

So do not worry, your hard drive is not the problem but the manufacturers that produced it.

If you wish to read more on this topic you can follow this link on hardware secrets.

Answered By 0 points N/A #125523

My hard drive Size is not correct ?


Determining the capacity of a drive confuses at times because the measurement standards often used are different.

The reason as to why you system is not displaying 160 GB instead of 149.04GB is  because there exists two different systems of measurement i.e. using decimal values where numbers are in base 10and also using binary values where numbers are in base of 2 .

For the sake of consistency and keeping it simple, 1mb is defined as 1 million bytes while 1GB is defined as 1,000 million bytes by the manufactures of the hard disk. This measurement is in the decimal format which happens to be the official industry standard. However, some system FDISK, BIOS, Windows and Mac equate a megabyte to 1,048,576 bytes while a gigabyte is equated to 1,073,741,824 bytes, this measurement is done in binary mode.

To determine capacity using the decimal mode, divide the total bytes by 1,000,000,000(this is the number of bytes that make up a gigabyte in decimal standards). 

To determine capacity using the binary mode, divide the total bytes by 1,073,741,824(This is the number of bytes that make up a gigabyte in binary standards). 

Because of this reason, you fill find out that different utilities give varying capacities yet it’s the same drive. The bytes will always be the same but when it comes to gigabyte it depends on which standards were used. This is the same to how 0 degree relates with a Fahrenheit of 32 degrees. The temperatures are the same but the scale in use depends the answer you get..

From the way you have described your problem; your computer’s operating system is displaying the hard drive capacity in binary form. By this I mean that the capacity indicated on the drive is the same as the one displayed by your operating system and no memory has been lost in that case.

Study the image below so that you can better your understanding further and be able to come up with a viable and logical conclusion.

Best Answer
Best Answer
Answered By 0 points N/A #125521

My hard drive Size is not correct ?


Hi Akhtar.

Hard drive manufacturers use the decimal system in specifying the drive size. That is,

1 gigabyte = 1,000,000,000 bytes

160 GB = 160,000,000,000 bytes

Whereas Windows specifies the drive size using binary system,. That is,

1 gigabyte = 1,024 bytes x 1,024 bytes x 1,024 bytes = 1,073,741,824 bytes per gigabyte

160,000,000,000 bytes / 1,073,741,824 bytes per gigabyte = 149.0116 gigabytes or 149 GB as reported by Windows!

The reason why hard drive manufacturers now use the decimal system is that it has become confusing for computer users what the size of a byte, kilobyte, megabyte, gigabyte, terabyte is. People who study computers know that 1kB = 1024 bytes. However, most people know that a kilo- if something is equivalent to a thousand.  For example, 1kg = 1,000 grams, 1km = 1,000 meters.  1kbyte = 1,024bytes just doesn't make sense to them.   Hence, the new definition of 1kB = 1,000 bytes was born and with it, all measurements of bytes changed as well.

Hope this helps.

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