Confused: Hard Drive Capacity's

  • Thread starter Thread starter Dave
  • Start date Start date
D

Dave

Hi

I would like some information on hard drive capacity's after installation in
Windows XP Home please.

Ok, I have just installed two (2) Seagate S-ATA hard drives on my MSI875P
motherboard and I would like to know if the capacity's of the drives after
installation is correct. The drives are ST380013AS (80GB system drive) and
the ST3120026AS (120GB additional storage) and are installed on SER1 and
SER2 of the motherboard.

I first installed the drives using Seagate Disk Wizard starter Edition (Easy
Installation) and the capacity's after installation of the drives are
(according to Seagate, Disk Wizard see's the drives as 1MB =1,000,000Bytes
and Windows see's 1MB =
1,048,576Bytes but that still does not explain the very large difference as
shown below):

80GB (System Drive):
As seen by Disk Wizard in Windows: 800028MB (Cluster size 4K Bytes)
As seen in DOS/FDISK: 76317MB
As seen in My Computer: 80,023,715,840 (74.5GB)

Question: I realise that the CMOS values are normally less that the values
seen in Windows but the drive is 80GB, buy why does it only show 74.5GB in
My Computer?

120GB (additional storage):
As seen by Disk Wizard in Wizard: 120039MB
As seen in DOS/FDISK: 11447MB
As seen in My Computer: 120,031,477,760 Bytes (111GB)
(Used: 71,258,112 Bytes (67.9MB)
(Free: 119,960,219,648 Bytes (111GB)

Question: The 120GB drive had no files on it after installation but the
space used was 67.9MB. Why?
Question: As with the 80GB drive but even more so, the capacity for this
120GB drive is shown as only 111GB. That's a difference of around 9GB on a
drive which had noting on it. Why?

BTW: I had two 80GB drives on the same system, one was the Seagate S-ATA
and the other was the Maxtor ATA133 and in My Computer, the drives are shown
as:

Maxtor 80GB: 81,956,655,104 Bytes (76.3GB)
Seagate 80GB: 80,023,715,840 Bytes (74.5GB)

So even here, there a around 2GB difference between the two 80GB drives?

I have installed many, many different makes of hard drives and there is
usually a reasonable difference in the purchased size to that shown after
installation but, 5.5GB for the 80GB and 9GB for the 120GB. That's some
difference. "Appears" that I'm not getting quite what I thought I was
purchasing ...... can anyone explain this please?

Regards

Dave
 
When XP use "GB" it means 2-to-the-30th-power, or
1,073,741,824

not 10-to-the-9th-power or 1,000,000,000.

For example, my nominally 120 Gig disks appear as 111.79 in the XP disk
management console.

I am a bit puzzled by the large amount of used space on a disk you know have
essentially nothing on it.

Did you use FDISK to partition and format the disk? If so, did you use the
version that can correctly handle disks larger than 64 Gig?

The Segate Disk Wizard should be able to handle such a disk, it did my 120
Gig SATA disk fine. Be sure that you downloaded the latest version. The
one that comes with the boxed hardware may be out of date even before it is
shipped.

I suggest that you consider using the XP disk management tool to remove all
parititions on the 120 Gig disk and re-create one or more partitions on that
disk, assuming that it is not your primary hard drive (i.e., the one with XP
on it).
 
Dave

Basically, as you have almost concluded, you are not missing any space -
although the drive manufacturer could
be clearer. For drive manufacturers 1,000,000,000 bytes = 1 Gb, whereas an
OS will regard 1,073,741,824 bytes as 1 Gb.

The best way to view this is in XP. Open My Computer, select the
appropriate drive and right-click,
select properties... beside 'capacity' you will see the total number of
bytes on your disk and to the right the number of Gigabytes.

For example, on my 120 Gb drive I have 120,023,252,992 bytes... which is
also listed in disk properties as a capacity of 111 Gb.

The Hard Drive manufacturer refers to the 'bytes' total in my case as 120
Gb... and, in purely decimal terms, it is - 120,000,000,000 bytes.

The 111 Gb is what the operating system (XP) 'sees'... because the OS
calculates 1024 bytes as 1 Kb, 1024 Kb as 1 Mb, and 1024 MB as 1 Gb.....

so in my case 120023252992 / 1024 / 1024 / 1024 (that's bytes => Kilobytes
=> Megabytes => Gigabytes) is 111 Gigabytes as far as the computer is
concerned.

Neither calculation of the disk size is 'wrong' ...... they are equivalent.

In your case, as you already know, the drive capacity of 80,023,715,840
bytes is referred to by 'My Computer' as 74.52 Gb after the above conversion
(The drive capacity may only show the first 3 digits.)

As for the variation in similar sized drives by different manufacturers,
well count yourself lucky... you got a bonus... by using the decimal
definition drive manufacturers are only obliged to provide 80,000,000,000
bytes when they claim a drive size of 80 GB.

As for the 67.9 MB space used... perhaps Seagate would be in a better
position to answer that.

Hope that helps
Pete
 
Hi Bob

Many thanks for your response to my hard drive capacity issue.

It's a relief to see that your 120GB disk is showing as 111.79 in the XP
disk management console ........ I just checked there and my 120GB drive is
showing exactly the same so (i.e. 111.79) so this is obviously how it turns
out after installation.

Yes, I did use both FDISK and the Seagate Disk Wizard (latest version) many
times because of the shortfall in the capacity but each time the reading was
the same, so I ended up installing the drive with the Seagate software.
With reference to the FDISK version used, it was the latest version
available and able to handle large disks up to 137GB.

And last but not least, with regard to your suggestion to use XP disk
management tool to remove all partitions (by the way, there is only one
partition on the 120GB drive), as you are getting the same capacity of
111.79GB on your 120GB drive, my only issue appears to be the 67.9MB of used
space on a brand new drive after format and, as I have already transferred
all my 'back-up' files to the drive, I will try your suggestion next time
around, but in the meantime, I will contact Seagate regarding that issue.

BTW, with the 111.79 capacity of the 120GB drive, does this mean that we
only have that amount of storage space instead of 120GB?

Regards

Dave
 
BTW, with the 111.79 capacity of the 120GB drive, does this mean that we
only have that amount of storage space instead of 120GB?
Click to expand...

Yes, you loose some to the formatting overhead.

Drive manufacturers are guilty of trying to edge each other out on
specmanship, and confusing (deliberately) their customers in the process.

This is why they spec 1G as 1,000,000,000 bytes, and not the proper binary
multiple.
Years ago, they used to quote "compressed capacity" making various
assumptions of what compression factor your might achieve.
 
Hi Pete

Many thanks to you for your response and, like Dave who also replied to me
and has a 120GB drive, you both agree that the capacity that I'm seeing for
my 120GB S-ATA drive is correct. I.e. 111.79GB in XP disk management
console or 111GB in My computer/Properties of the drive.

With reference to the 67.9MB of used space on the 120GB drive after format,
I first installed the disk using the Seagate software in Windows and when I
checked the capacity and saw that 67.9MB had already been used, I then used
FDISK to delete the partition and then created another, booted into XP and
formatted the drive but upon checking the capacity, 67.9MB had still been
allocated for something on the disk but that's a mystery to me, but I'd like
to know what and I will take this issue up with Seagate.

Regards

Dave
 
Hi Dave

Thanks for the follow up Dave.

You may want to try the Disk Management method of installing and formatting
the drive rather than FDisk or the Seagate software.

Right-click on "My Computer" and select "Manage".
Disk management is listed under Storage on the left
Select 'disk management'
The new drive should appear in the right hand panel
Right-click the drive to select.
Delete the partition there and you should then be able to repartition and
reformat (NTFS usually).

Seagate provide instruction on how to use XP Disk management to install a
new drive
(or the help pages in disk management should be helpful)

http://www.seagate.com/support/kb/disc/howto/install_xp_disk_mgmt.html

Hope that helps
Pete
 
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