# WD 160GB Quest for Confirmation

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April 15, 2007 6:27:24 AM

Does anyone know why 2 X 160GB WD hard drives in Raid 0 would be only showing 298GB?

I believe these drives may only be 150GB capacity yet they are labeled 160GB...
April 15, 2007 6:52:39 AM

It's the way the term Gigabyte is used. When a company says gigabyte, they mean 1 billion bytes, or 1,000,000,000. In windows, a gigabyte is represented as 1,073,741,824 bytes. When you format a hard drive, windows see's the space in it's true GB value, and not the GB value advertised.

this is the reason your drives appear to have less space.
April 17, 2007 3:18:28 AM

Quote:
It's the way the term Gigabyte is used. When a company says gigabyte, they mean 1 billion bytes, or 1,000,000,000. In windows, a gigabyte is represented as 1,073,741,824 bytes. When you format a hard drive, windows see's the space in it's true GB value, and not the GB value advertised.

this is the reason your drives appear to have less space.

Not following you on that... what you are saying is that I should see even more in windows- If windows sees 1GB as 1,073,741,824...

?
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April 17, 2007 4:09:27 AM

Each HD is 160,000,000,000 (160 billion) bytes. Together in the RAID 0 they are 320,000,000,000 (320 billion) bytes.

Using the manufacturer's definition of GB (1 GB = 1,000,000,000 bytes), you have a reported capacity of 320,000,000,000 / 1,000,000,000 = 320 GB.

Using Window's definition of a GB (1 GB = 1,073,741,824 bytes), you have a reported capacity of 320,000,000,000 / 1,073,741,824 = 298.02 GB.

But the reporting doesn't really matter. You paid for (and received) 320,000,000,000 bytes of capacity. You can report that in Windows GB, hard drive GB, Hostess GigaTwinkies, or Little Debbie's GigaCupcakes and it's still 320,000,000,000 bytes at the end of the day.
April 17, 2007 4:46:45 AM

The lost space is from formatting. Although the hard drives can "theoretically" hold 320 gb, the extra space is taken up by the formatting.

PS- Its just the way it is....all file systems take up space.
April 17, 2007 10:08:06 PM

Quote:
The lost space is from formatting. Although the hard drives can "theoretically" hold 320 gb, the extra space is taken up by the formatting.

PS- Its just the way it is....all file systems take up space.

April 17, 2007 11:21:28 PM

I was goin' old skool there.....
Back in the days of FAT file systems, the formatting used a considerable amount of slack space.....your saying NTFS doesn't do this?
April 17, 2007 11:54:38 PM

All file systems reserve some space, but today that space is so insignificant compared with the size of today's hard drives that the decrease in capacity you see is not from the file system structures.

The primary culprits of seeing less space when a drive is formatted from the advertised size are: The above indicated reporting difference between GB (10^9) and GiB (2^30), and creation of Windows system files on the drive, such as the pagefile and/or the Windows hibernate file.

NTFS itself initially reserves very little for the MFT, volume bitmap, Log file, etc. On a brand-new formatted volume, it's typically less than 50MB.
April 18, 2007 1:16:59 PM

i was just about to say what SomeJoe7777 said.
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