Computer Hope

Hardware => Hardware => Topic started by: Aldom92 on February 02, 2008, 09:30:42 PM

Title: missing hard drive space
Post by: Aldom92 on February 02, 2008, 09:30:42 PM

hello everyone.  i have a 160GB hard drive divided into two partitions (i bought the computer with the hard drive already in it and partitioned).  C: is 145GB and d: is 3.74GB. in the bios it detects the full 160. so my question is... wheres the rest of my space?  oh, and i already checked disk management too and disk properties.  i have xp pro. thanks for any help 

Title: Re: missing hard drive space
Post by: Broni on February 02, 2008, 10:38:09 PM

It's all about Decimal vs. Binary measurements...

For simplicity and consistency, hard drive manufacturers define a megabyte as 1,000,000 bytes and a gigabyte as 1,000,000,000 bytes. This is a decimal (base 10) measurement and is the industry standard.
A decimal capacity is determined by dividing the total number of bytes, by the number of bytes per gigabyte (1,000,000,000 using base 10).

However, certain system BIOSs, FDISK and Windows define a megabyte as 1,048,576 bytes and a gigabyte as 1,073,741,824 bytes. These are binary (base 2) measurements.
A binary capacity is determined by dividing the total number of bytes, by the number of bytes per gigabyte (1,073,741,824 using base 2).

This is why different utilities will report different capacities for the same drive. The number of bytes is the same, but a
different number of bytes is used to make a megabyte and a gigabyte.

For instance...
Various Drive Sizes and their Binary and Decimal Capacities

Drive Size in GB Approximate Total Bytes Decimal Capacity   |   Approximate Binary Capacity (bytes/1,073,724,841)
(bytes/1,000,000,000) 

10 GB ----------------------------------------------------------------------------9.31 GB
20 GB -------------------------------------------------------------------------- 18.63 GB
30 GB -------------------------------------------------------------------------- 27.94 GB
40 GB -------------------------------------------------------------------------- 37.25 GB
60 GB -------------------------------------------------------------------------- 55.88 GB
80 GB -------------------------------------------------------------------------- 74.51 GB
100 GB ------------------------------------------------------------------------ 93.13 GB
120 GB ----------------------------------------------------------------------- 111.76 GB
160 GB ---------------------------------------------------------------------- 149.01 GB
180 GB ----------------------------------------------------------------------- 167.64 GB
200 GB ----------------------------------------------------------------------- 186.26 GB
250 GB ----------------------------------------------------------------------- 232.83 GB                                                       

Title: Re: missing hard drive space
Post by: Aldom92 on March 10, 2008, 06:44:47 PM

thanks a lot. i guess i shouldve thought about that. very well explained. thanks again

Title: Re: missing hard drive space
Post by: Aegis on March 10, 2008, 06:50:27 PM

Yes, very nice explanation!  I'd read infomation about that a long time ago, and forgotten too much of it!  ::)

Title: Re: missing hard drive space
Post by: Broni on March 10, 2008, 06:54:35 PM

Wow! MiA for over a month?

Title: Re: missing hard drive space
Post by: squall_01 on March 11, 2008, 04:40:49 AM

The BIOS isn't ment to see that just what ever hardware is attached to the system

Title: Re: missing hard drive space
Post by: Broni on March 11, 2008, 09:45:37 AM

Quote

The BIOS isn't ment to see that just what ever hardware is attached to the system

??