Dumb Computer Question!

[Harry Tuttle]

I just installed a 200GB hard drive. It has 200,000,000,000 bytes on it, but is shows up as 186GB. Why's that again?

[Dis]

why is your computer dumb?

[mrmitchell]

It doesn't really have 200,000,000,000 bytes on it. It really has 2^(somethingth) power bytes, which is closer to 186GB.

I think.

[Koyaanisqatsi]

For marketing purposes, somebody somewhere decided that 1MB equals 1,000,000 bytes rather than 1,048,576 bytes, which it should be. So drives tend to be listed by the marketing meg when sold, but computers still read the correct one.

[Harry Tuttle]

Originally posted by Koyaanisqatsi
For marketing purposes, somebody somewhere decided that 1MB equals 1,000,000 bytes rather than 1,048,576 bytes, which it should be. So drives tend to be listed by the marketing meg when sold, but computers still read the correct one.

Ahhh, I see. Thank you

[snoopy369]

Actually, it's because formatting a drive takes up some of the capacity with the filesystem and such. I believe a 200GB drive has pretty close to 200,000,000,000 bytes available on it (in fact, iirc 1 GB = 1,000,000,000 bytes exactly, not 2^30, whereas 1MB = 2^20 bytes, at least according to HDD peoples). Formatting it under different filesystems (NFTS, FAT32, various Unix filesystems and Mac filesystems, etc.) will yield different final amounts.

This is true on any disk, be it a HDD, floppy, or even a SD card for a camera - you need to save some room for the FAT and other niceties, and those come out of the total disk volume.

Edit: lol! Apparently it's both... I was under the impression that Windows used 1GB=1x10^9 as a gigabyte, but it apparently doesn't ... so some of your missing space is filesystem, and some is 1x10^9/2^30.

Edit2: Hmm, and windows is lying to you, in telling you it's 186GB. That's the correct number under Koy's answer above - but it definitely should be telling you that some of the space is taken with filesystem and whatnot; in past iterations of windows, and other programs, it's been consistent that way. Apparently it doesn't any more