Computer newbies forum: 160GB HDD when formated is 149GB....

THE ANALOGY: Whether your height is reported in feet or meters, you don't get any taller or shorter.

1,000,000,000 bytes = Decimal GB
1,073,741,824 bytes = Binary GB

So, one Decimal GB = 0.93132 Binary GB

The hard drive size printed on its retail packaging is a count of the bytes reported in units of Decimal GB. The hard drive size reported by Windows is a count of the same number of bytes, but with different units of measurement, namely the Binary GB.

So, you can expect Windows to display the size of any hard drive at about 93% of the advertised number of GB (or almost 7% fewer GB).

Some who encountered this issue decided to join a class action lawsuit to feel good:
http://www.google.com/search?hl=en&q=western+digital+lawsuit+gigabytes&btnG=Search

No one felt as good as the two lawyers who took in half a million dollars!

The lawyers usually do come out richer, while everyone else gets a few dollars. That class action was a joke, a waste of time and tax payers money. Anyone with half a brain and a few minutes of time with Google, would be able to understand why there is a disk space difference between an unformatted and formatted drive.

ok can someone please explain as follows. seagate 160gb reads in bios as a 160gb. and when i partition it fat32 it comes out a 159999... thats using a disk manager like ibm v9.7 or something. i dont have a partion manager that does ntfs at this time. so i place my win 7 dvd in and when i get to the part where i need to format my drive it reduces to 149gb. fat32 it was all there. ntfs for win 7 its smaller. so i tried it using 2 partitions on the disk. results are instead of having 1 x 80gb and 1 x 79.9gb partition i have a 74.5gb and a 74.4gb partition. and windows with all of its updates takes up 16.2 gb. that seems unusually high. should i disable shadowing in bios and what else should i enable and disable? or should i just go back to xp where the partition was correct at fat32? 16.2 gb is just windows 7 with all of the updates and mse security essentials. nothing else on there. the hdd ran quiet on auto. now its not as quiet on LBA on a yeston P35 mobo, 2gb ram, 1.8 core duo. the seagate tools were useless even with another seagate. that 80gb reports as 80gb running windows xp. help please anyone?

As you have already read, but here is the math (somewhat simplified, but if you know of the 'powers of 2' you'll understand):
160,000,000,000 / 1024 /1024 /1024 = 149.01 G

As I understand it, the 48-bit LBA problem can be a hardware and/or software problem.

Reference: http://www.48bitlba.com

The original version of XP (no service pack) didn't have support for hard drives over 137GB (formatted as 127GB).

This was fixed in with XP-SP1.

Reference: http://www.48bitlba.com/issues.htm

The 149GB issue is a different issue (see Post #2).

Bob

The part about the difference between the drive mfr using decimal Gigabyte vs MS in all but one place using Binary Gigabyte is one hundred percent correct.

There is one place where it reports the decimal number. I simply forget where that is, believe it was related to FDISK or format in older versions.

The number provided by the drive mfr, is the minimum guaranteed number of bits, in the DECIMAL NUMBER SYSTEM, AVAILABLE FOR FORMATTING. The drive's plattters, when made, have a little more space [more bits]to allow for the loss of some sectors due to manufaturing defects.

Yes formatting will lose some space, however the large difference is due to the use of different number systems.

The 250GB hard drive that the operating system displays as 232GB contains the same total number of bits before and after formatting. The significant difference results from using two different systems of measurement (decimal and binary).

The computer I am using right now is running fully updated XP Pro with SP2. It has a 160GB hard drive. If I right-click on the hard drive icon and select Properties, the total capacity is listed as "160,031,014,912 bytes" and it is also listed as "149GB" in that same Properties window.