150 Gigs from 160 Gig Disk - Missing Disk Space

[PointOnePA]

I've already checked the postes under "Where did all my hard disk space go?" and that thread does not appear to apply to my problem.  "No Backups Found" under Rescue and Recovery.

I have a new Thinkpad T61 with a 160 Gig Hard drive (Hitachi HTS722016K9SA00).  Disk manager shows two partitions: EISA Configuration 6.23 GB and NTFS (Cdrive) 142.81 GB.  This only adds up to about 149 GB, so I'm looking for a missing 10 Gigs.

I've made backup DVD of the system files and I checked Rescue and Recovery and no backups exist.  Using Windows Explorer, I check the properties of the C drive and its folders.  The properties of the C drive state 25.8 Gigs used.  But when I add up the total usage of all of the subfolders, it only comes to 16 Gigs, mainly in SWSHARE, SWTOOLS, WAUUPGRD, Windows.  So 9.8 Gigs is unaccounted and I have the view configured to show ALL files system or otherwise.

I don't know if these problem are related, but if anyone has a suggestion to find the missing space I would appreciate it.

PointOnePA
g9u5dd43@yahoo.com
 

[sktn77a]

Binary vs decimal.  All hard drives have less than their stated capacity.  Your 150Gb sounds about right for a "160Gb" drive.

[erik Community SuperMod]

you aren't missing anything.   149GiB of available file storage is equal to 160GB of available hard disk drive space because they are measured using two different standards.   you have to multiply 149GiB by 1.073741824 to get 160GB.

http://en.wikipedia.org/wiki/Gigabyte#Consumer_confusion

[1981camaroz28]

You have a 160gb unpartitioned when you format a drive you loose space. There is things you don't see like the File Allocation Table. On a 40gb drive you get about 32gb of space.

[andyP Community SuperMod]

As information you could also look at this 59,2KB pdf by James Wiebe;  "When One Billion does not equal One Billion".

[erik Community SuperMod]

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1981camaroz28 wrote:
You have a 160gb unpartitioned when you format a drive you loose space. There is things you don't see like the File Allocation Table. On a 40gb drive you get about 32gb of space.

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that is incorrect.   formatting doesn't take any space and the file allocation table only requires a few bits.   i have a 750GB external drive formatted NTFS and all 750GB are available.   here is the math...

advertised drive size: 750.00 GB
partition #1: 128.00 GiB (formatted NTFS)
partition #2: 570.63 GiB (formatted NTFS)
total volume: 698.63 GiB

if you take 698.63 x 1.073741824 as i mentioned above, you get 750.14825GB -- the advertised drive size.   using the same math, a 40GB drive will report as 37.25GB in windows whether formatted or not.

the confusion comes from microsoft incorrectly reporting GiB as GB.   please read the link in my post above to better understand the difference.

[PointOnePA]

I understand the math and the reason for the apparent discrepency.
Thanks all.