Results 1 to 10 of 10
  1. #1
    2 Star Lounger
    Join Date
    Dec 2009
    Location
    Scotland
    Posts
    119
    Thanks
    0
    Thanked 0 Times in 0 Posts
    I am running windows 7 home version. I have two hard drives which are 500gb's in size but both report the true size as 465gb's. I understand that the operating system will take up some space on the C drive but what would be taking up the same space on the other drive? I have only one operating system installed. TIA

  2. #2
    Super Moderator CLiNT's Avatar
    Join Date
    Dec 2009
    Location
    California & Arizona
    Posts
    6,121
    Thanks
    160
    Thanked 609 Times in 557 Posts
    The NTFS file system will take up some overhead once a drive has been formatted with it.
    There is also the matter of conversion of bytes to Gigabytes.
    DRIVE IMAGING
    Invest a little time and energy in a well thought out BACKUP regimen and you will have minimal down time, and headache.

    Build your own system; get everything you want and nothing you don't.
    Latest Build:
    ASUS X99 Deluxe, Core i7-5960X, Corsair Hydro H100i, Plextor M6e 256GB M.2 SSD, Corsair DOMINATOR Platinum 32GB DDR4@2666, W8.1 64 bit,
    EVGA GTX980, Seasonic PLATINUM-1000W PSU, MountainMods U2-UFO Case, and 7 other internal drives.

  3. #3
    2 Star Lounger
    Join Date
    Dec 2009
    Location
    Scotland
    Posts
    119
    Thanks
    0
    Thanked 0 Times in 0 Posts
    Thanks. I "broadly" understand what the link states but why are the two drives the same size when one has an operating system installed and the other doesn't?

  4. #4
    4 Star Lounger
    Join Date
    Dec 2009
    Location
    Fishkill, New York, USA
    Posts
    435
    Thanks
    96
    Thanked 35 Times in 31 Posts
    I think the 465 GB number is your drive capacity. Do a properties on the C: drive to find out how many bytes are being used and then compare to your other drive.

  5. #5
    Super Moderator bbearren's Avatar
    Join Date
    Dec 2009
    Location
    Polk County, Florida
    Posts
    3,759
    Thanks
    26
    Thanked 424 Times in 338 Posts
    Hard Drive manufacturers sell their wares by listing the capacity in decimal numbers. Operating systems recognize hard drive capacity in binary numbers.

    A Byte is 8 binary bits, derived by definition as 2^3, 2X2X2. To Seagate et al, 1,000,000,000 bytes is labeled as a Gigabyte strickly for sales purposes; the operating system will never see those numbers. To an operating system, a Gigabyte is measured as 2^30, or 1,073,741,824 Bytes. 500,000,000,000 / 1,073,741,824 = 465.66.

    I have a USB external Seagate "750 GB" drive that Windows sees as a 698 GB drive. Most of the missing 52GB went up in advertising smoke.

    The displayed Windows drive sizes are determined using binary, not decimal, and the total size is listed as the number of formatted binary GB physically on the disk, (rounded off to significant digits determined by drive size). The free space shown is the number of GB physically on the disk that have been allocated by the file system but not yet written. Not shown is the space occupied by the NTFS indexes, metafiles, MFT and NTFS log file, otherwise known as file system overhead.

    Create a fresh drive image before making system changes, in case you need to start over!

    "The problem is not the problem. The problem is your attitude about the problem. Savvy?"—Captain Jack Sparrow "When you're troubleshooting, start with the simple and proceed to the complex."—M.O. Johns "Experience is what you get when you're looking for something else."—Sir Thomas Robert Deware.
    Unleash Windows

  6. #6
    2 Star Lounger
    Join Date
    Dec 2009
    Location
    Texas
    Posts
    162
    Thanks
    0
    Thanked 2 Times in 2 Posts
    bbearren good explanation. I couldn't have said it better.

  7. #7
    2 Star Lounger
    Join Date
    Dec 2009
    Location
    Scotland
    Posts
    119
    Thanks
    0
    Thanked 0 Times in 0 Posts
    Thanks for the feedback.

  8. #8
    Super Moderator BATcher's Avatar
    Join Date
    Feb 2008
    Location
    A cultural area in SW England
    Posts
    3,413
    Thanks
    33
    Thanked 195 Times in 175 Posts
    Worth reading is the Wikipedia information about Gibibytes and Gigabytes (among others), together with the Table of Prefixes and the "See also".

    "IEEE 1541-2002 is a standard issued by the Institute of Electrical and Electronics Engineers (IEEE) concerning the use of prefixes for binary multiples of units of measurement related to digital electronics and computing.", and has been out for over eight years. Very few people seem to know about it or use it...
    BATcher

    Time prevents everything happening all at once...

  9. #9
    Super Moderator bbearren's Avatar
    Join Date
    Dec 2009
    Location
    Polk County, Florida
    Posts
    3,759
    Thanks
    26
    Thanked 424 Times in 338 Posts
    Quote Originally Posted by BATcher View Post
    Worth reading is the Wikipedia information about Gibibytes and Gigabytes (among others), together with the Table of Prefixes and the "See also".

    "IEEE 1541-2002 is a standard issued by the Institute of Electrical and Electronics Engineers (IEEE) concerning the use of prefixes for binary multiples of units of measurement related to digital electronics and computing.", and has been out for over eight years. Very few people seem to know about it or use it...
    If you could buy a 500 GB drive for the same price as 465 GB drive, which would you choose? How about a 1 TB drive vs a 931 GB drive for the same price?

    It's all marketing, aimed toward folks that don't fully appreciate the difference between binary math and decimal math, and probably don't understand that computers only "see" 1's and 0's.
    Create a fresh drive image before making system changes, in case you need to start over!

    "The problem is not the problem. The problem is your attitude about the problem. Savvy?"—Captain Jack Sparrow "When you're troubleshooting, start with the simple and proceed to the complex."—M.O. Johns "Experience is what you get when you're looking for something else."—Sir Thomas Robert Deware.
    Unleash Windows

  10. #10
    Gold Lounger Roderunner's Avatar
    Join Date
    Dec 2009
    Location
    Scotland.
    Posts
    3,462
    Thanks
    16
    Thanked 216 Times in 183 Posts
    Various Drive Sizes and their Binary and Decimal Capacities

    Drive Size Approximate Total Bytes Decimal Capacity
    (bytes/1,000,000,000)

    Approximate Binary Capacity (bytes/1,073,724,841)
    10 GB___ 10,000,000,000__ 10_ GB___ 9.31 GB
    20 GB___ 20,000,000,000__ 20_ GB__ 18.63 GB
    30 GB___ 30,000,000,000__ 30_ GB__ 27.94 GB
    36 GB___ 36,000,000,000__ 36_ GB__ 33.53 GB
    40 GB___ 40,000,000,000__ 40_ GB__ 37.25 GB
    60 GB___ 60,000,000,000__ 60_ GB__ 55.88 GB
    74 GB___ 74,000,000,000__ 74_ GB__ 68.91 GB
    80 GB___ 80,000,000,000__ 80_ GB__ 74.51 GB
    100 GB_ 100,000,000,000_ 100_ GB__ 93.13 GB
    120 GB_ 120,000,000,000_ 120_ GB_ 111.76 GB
    150 GB_ 150,000,000,000_ 150_ GB_ 139.69 GB
    160 GB_ 160,000,000,000_ 160_ GB_ 149.01 GB
    180 GB_ 180,000,000,000_ 180_ GB_ 167.64 GB
    200 GB_ 200,000,000,000_ 200_ GB_ 186.26 GB
    250 GB_ 250,000,000,000_ 250_ GB_ 232.83 GB
    300 GB_ 300,000,000,000_ 300_ GB_ 279.40 GB
    320 GB_ 320,000,000,000_ 320_ GB_ 298.02 GB
    400 GB_ 400,000,000,000_ 400_ GB_ 372.52 GB
    500 GB_ 500,000,000,000_ 500_ GB_ 465.65 GB
    1 TB (1000 GB) 1,000,000,000,000_ 1 TB (1000 GB) 931.30 GB
    O wad some Power the giftie gie us, to see oursels as ithers see us!

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •