XP wont recognice full size of hd

[doubledragon5]

I know this question has been asked before, but I'm confused. Xp will not recognize the full capacity of both my 120GB WD SE and my 100GB WD SE hard drives. The 120 is recognized as 111GB and the 100 is recognized as 93.1 GB WHY WHY WHY???. The bios recognizes the rull capacity of the hd how come not xp. When XP was installed on the hard drives I let it partition and format both drives, I would think it would recognizes both as they are.

[not important]

It's the way the HDD manufactures figure the size. as opposed to real size. My 40G is recognized as 37.9

[ktkendall]

I think it's the old 1024 bytes in 1kbyte, as windows measures the capacity but the HD manufacturer lists it's cap using 1000 bytes to 1kbyte...

[doctorgonzo]

When the hard drive manufacturers say 100GB, they mean 100,000,000,000 bytes.

However, the more common definition of a KB is 1,024 bytes, not 1,000; for a MB, 1,048,576 bytes, not 1,000,000; and for a GB, 1,073,741,824 bytes, not 1,000,000,000. These amounts are based on powers of 2, which makes sense for binary computers.

If you divide the manufadturer's amount of 100,000,000,000 by 1,073,741,824 you get 93.13, exactly what Windows is reporting. Similarly, if you divide 120,000,000,000 by 1,073,741,824 you get 111.76, again what Windows is reporting. So there is nothing wrong with your PC. It is just confusing that the same unit of measurement has two different values.

[doubledragon5]

Thanks doc I understand the whole thing. Knowing this will help me to help others in the future if they have the same problem.

Thanks everyone

[tigstah]

took me a while to figure that out also

[sramesh2k]

Hard drives are marketed in terms of decimal (base 10) capacity. In decimal notation, one megabyte (MB) is equal to 1,000,000 bytes, and one Gigabyte (GB) is equal to 1,000,000,000 bytes. The decimal system is what we are accustomed to in everyday life.

However, computers (and programs such as FDISK) use the binary (base 2 numbering system. In the binary numbering system, one megabyte is equal to 1,048,576 bytes, and one gigabyte is equal to 1,073,741,824 bytes.

DOS FDISK and Apple's operating system (MAC O/S) use the binary numbering system. When determining hard drive capacities with FDISK, one should multiply the value shown in FDISK (displayed in base 2 megabytes) by 1,048,576 to determine the decimal equivalent for the hard drive's capacity.

Here is an example (using a 20.5GB ATA/IDE drive):

FDISK displays the capacity of your hard drive as 19603 Mbytes. This value represents the base 2 or binary capacity of the disk drive. To determine the equivalent base 10 or decimal capacity, multiply 19603 by 1,048,576. This results in a value of 20,555,235 bytes or approximately 20.5GB in decimal terms.

Microsoft usually defines a gigabyte as 1024*1024*1024 (or 1,073,741,824) bytes.

Maxtor, Iomega, and Western Digital define a gigabyte as 1000*1000*1000 (or 1,000,000,000) bytes.

Seagate defines a gigabyte as 1024*1000*1000 (or 1,024,000,000) bytes.


http://h20015.www2.hp.com/en/documen...cName=bpb11117