Disk capacity discrepancy with ext4

[jcd29]

I've been seeing this with every single ext4 or ext3 disk/partition I work with, but I decided to make a post about it now since I got a bigger hard drive.

I formatted a 1TB external HDD as ext4 last night.

This is what I got:

img146.imageshack.us/img146/2259/71163295.png

img69.imageshack.us/img69/7180/70755142.png

The first imaage is from GParted, and the second one from Nautilus, when you right click the disk and click on Properties. Notice how GParted says the disk is 931 GiB while the Properties window says it's 917 GB. This happens to every single ext4 or ext3 drive I've worked with, and every other Linux computer with ext4 or ext3 I've seen. I know about the 5% reserved space in ext4, but it's not that. The 5% would be that 45.8 GB you see as used (the disk in actually empty) in the Properties image.

Now, I know about how HDD manufacturers will tell you it's 1000TB when in reality it's not, etc. The thing is, according to this converter: wintelguy.com/gb2gib.html

1000 GB would be 931 GiB. So far so good! The GParted image shows the disk as 931 GiB. The thing is, as you can see, it also shows 14.81 GiB used right out of the gate, which leaves that 917 GiB that the Properties image takes as the "total capacity".

So what's going on here? Is it just that ext4 takes that much off the actual disk capacity? Because I compared with a friends 1TB external, and it showed its total capacity as 931 in both GParted AND the disk properties, but of course his disk was NTFS.

It'd be weird if ext4 takes off 14 GiB while NTFS takes nothing, so I'm wondering what exactly is that and if it can be changed/fixed somehow?

[Rubberman]

The system reserves about 10% of the disc space for root in order to do file management, so users will see less available space than is physically available.