160gb hard drive not giving full capacity

[shahan]

I have just installed a new 160gb Western Digital hard drive but it is not giving me the full 160gb. In the bios it says 137.4gb and in 'My computer' it shows as 149gb with 69.1 mb used.

Also in Windows XP under 'disk management' in control panel when its first installed or i try to format it a 'dynamic disk and volume wizard' popups to create the disk as a dynamic disk and a volume. So, then i formatted it, also it doesnt support partioning the drive and when formatting it only lets you format in NTFS file system, there is no FAT32.

The drive is installed as a secondary slave with a DVD-rewriter as the primary device. I had other hard drives on the same channel in the same setup and there was no problem. The 2 other disks show 'basic' disks and not 'dynamic' disk in 'disk management'

The system thinks i want to use this hard drive as a dynamic disk as part of a RAID system.

[SuperSparks]

As for the space reported, it's simply a matter of how you measure a Gigabyte - the binary way, which is 1024 ^ 3 = 1,073,741,824 bytes, or the decimal way which is 1000 ^ 3 = 1,000,000,000. Windows always reports the binary way, whereas drive manufacturers use the decimal way. As the decimal method of calculating the drive size is the ISO standard, you should really just look upon it that Windows is underreporting the drive size.

Windows XP limits the size of volume that it will format in FAT32, if you really must use FAT then you'll need to use 3rd party tools. I'd strongly advise using NTFS, it is a vastly better filesystem.

[Doc]

SuperSparks is correct in how Windows calculates the space.

As to the FAT 32 issue you can partition the drive into 2 or more partitions and then format each using FAT 32. Unless you need FAT 32 for some reason, such as running Linux, or dual booting DOS or Win 95, you are better off with NTFS.

Doc

[Broni]

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

[SpywareDr]

In the bios it says 137.4gb

The original design specification for the ATA interface only provided 28-bits with which to address the devices. This meant that a hard disk could only have a maximum of 268,435,456 sectors containing 512 bytes of data per sector thus limiting the ATA interface to a maximum of 137,438,953,472 bytes (137.4 GB). With 48-bit Logical Block Addressing (LBA) the limit is 144 PetaBytes (144,000,000 GigaBytes).

In order to use 48-bit LBA, it must be supported by both the BIOS and the Operating System, (and of course the drive itself).

More info:

http://www.dewassoc.com/kbase/hard_drives/lba.htm

http://en.wikipedia.org/wiki/Logical_block_addressing

http://support.microsoft.com/kb/303013

http://support.microsoft.com/kb/126855

[shahan]

So, i do acutally have the full 160gb but i am just not seeing it in the BIOS and in XP ? and i dont have buy a seperate controller card?

(this is my motherboard: 'Gigabyte GA-71XE4')

If i needed the ultra ATA/33 compatible PCI card, is this what i should get:
http://www.novatech.co.uk/novatech/specpage.html?NOV-ATA133 ?

If i am not seeing the full 160gb but it is actually there how would i know whether i am really or not using the full capacity because XP could be telling me anything?

[Steve R Jones]

Have you read through the links SpywareDr posted?

[shahan]

SuperSparks is correct in how Windows calculates the space.

As to the FAT 32 issue you can partition the drive into 2 or more partitions and then format each using FAT 32. Unless you need FAT 32 for some reason, such as running Linux, or dual booting DOS or Win 95, you are better off with NTFS.

Doc

it doesnt even let me choose between the two, i only have NTFS as the option. The reason i like FAT32 is because in case the system goes down i can use a Windows98 boot CD and access the system in dos mode and have access to all my data. Whereas with NTFS its a lot of hassle but i do keep my main xp operating system drive/partition as NTFS. I dont find XP boot cd/disc or the command line in safe mode helpful and its very limited.

[SpywareDr]

GIGABYTE > Support > Motherboard > FAQ of GA-7IXE4
http://tw2005.giga-byte.com/Motherbo...Q_GA-7IXE4.htm

262 Can this MB support 80G HDD or higher? ... More

GIGABYTE > Support > Motherboard > FAQ Details
http://tw2005.giga-byte.com/Motherbo...AQ/FAQ_262.htm

[Q] Can this MB support 80G HDD or higher?

[A] Please update the latest version BIOS.

GIGABYTE > Support > Motherboard > BIOS > BIOS of GA-7IXE4
http://tw2005.giga-byte.com/Motherbo...S_GA-7IXE4.htm

How to reflash M/B BIOS?

Download Version F9 (2001/11/12)
http://tw2005.giga-byte.com/Download.../bios_7ixe4_f9

Note that Windows 2000 would need to be upgraded to SP3 (Service Pack 3) and Windows XP to at least SP1 (Service Pack 1) in order to use hard drives larger than 137GB.

--

One of the main reasons for using NTFS instead of FAT32 is because the largest file size in FAT32 is 4GB.

[SuperSparks]

A 160GB drive will be reported in Windows as 149GB, so all of the drive is being used:

160GB = 160000000000 bytes.
160000000000 / (1024^3) = 149.011GB, which is what you are seeing in My Computer.

Ignore what the BIOS says, that is immaterial.

[SpywareDr]

What is shown as the "Capacity" in "bytes" in XP's Windows Explorer? (Right-click the drive icon in "My Computer" and select "Properties").

For example:

[shahan]

ok, thanks. but what is that '^' sign ? can i get it on a calculator?

i will let you know the capacity in bytes when i get back from home.
but do i have to update the bios, that being a dangerous task.

[shahan]

so, according to gigabyte this motherboard does not support hard drives larger than 80gb or is it the decimal vs binary calculations?

160GB = 160000000000 bytes.
160000000000 / (1024^3) = 149.011GB, which is what you are seeing in My Computer.

[shahan]

I have a another 80gb hard drive in the pc and BIOS says it is '80.0 gb' but in XP it reports 74.3 gb.

If it truly does not support anything larger than 80gb, then its a different and physcial problem and i may have to perform the dangerous task of flashing the bios.

also if windows is under-reporting the size, then what if i am trying to fit 160gb and windows stops at 149gb and says thats it, you cant put any more data on the disk?

[jerryctx]

My apologies if I'm stating the obvious but some readers may not understand that the binary and decimal counts can be different yet they represent the same quantity. The same is true for all radix/base number systems.

Lets compare decimal (base 10) to octal (base 8). Its a lot easier to follow than binary:

The decimal digits followed by octal digits:

0 1 2 3 4 5 6 7 8 9 10 ...
0 1 2 3 4 5 6 7 10 ...

So decimal 8 is equal to octal 10. As someone joked "Octal is just like decimal if you're missing two fingers." Since there is no 8 or 9 in octal counts jump from 7 to 10.

Your 160/140 values represent the same physical disk size. You haven't lost any capacity, its just being counted in 2 different ways. Sort of like Arabic versus Roman numerals; you have 10 toes, ancient Romans had X toes but you both have the same quantity of toes.