Shrinking Hard Drive?

Umm, is this right?

I boought a 750GB external hard drive when I bought my Mac a few months ago but I just looked at it and Finder is saying that it's capacity is only 596.18GB (it's formatted as HFS+). Now I know that any drive once formatted is going to be smaller than unformatted capacit but to loose the best part of 153GB to formatting seems a tad excessive, doesnt it?

Yea that can't be the formatting, that's ridiculous.

Perhaps you have a small partition?

Losing 20% (unless the hard drive is defective with isolated bad sectors facing imminent failure) to formatting would be truly astonishing.

This may sound silly, but you aren't using it are you? Is it reporting the free disk space to you (as opposed to the entire size of the drive)? Or if you just formatted it, do you know if there's a 'special' partition: pre-installed software for security, hibernation partition, etc?

yh most likely (as others haver said)

a partition you cant see.
or
only showing free disc space.

post a screen shot of what its showing.

All I'm doing is Opening Finder, right clicking on the drive and selecting Get Info.

This brings up a window that says:
Capacity 596.18GB
Available 397.39GB
Used 198.79GB

This is a drive that I bought from Apple and that came preformatted as HFS Extended. How can I find out if there are any hidden partitions etc on it?

Send it back.

There's no way that is correct! If it had a windows formatted partition then it would show up on in osx ayway.

I'm sure you've already done it, but open disk utility and have a look at the partition info.

Well, I just did a bit of number crunching. About 99% of drives I ever see don't actually have XXX Binary Gigabytes of storage.

If it is a true 750 GB drive, then it would have 805306368000 bytes of storage. This is following the binary 1024, not the base-ten 1000 multiple. Likely it is using base-ten, making it actually have 750000000000 bytes of storage, which works out to a true 698.491930962 GB.

I've experienced this firsthand when I got myself a 320GB drive, and when I use Linux's cfdisk to partition it (I prefer cfdisk over fdisk, for the Linux-users out there), I can see the exact bit-age, and see that it was closer to 300GB.

So, if it is following the regular standard of Base-ten, then it is a 14.65% loss, rather than the 20.51% loss if it is a true 750GB drive. if it came with more packaging than an electrostatic plastic bag, then check if it says anywhere on it something like "1GB = 1000000000 bytes". if it does, then technically, they are correct, as that is a true usage. it's all a marketing game.

Slokunshialgo, while you are correct about hard drive companies using base 10 (as opposed to every OS using base 2) resulting in "loss" of space, losing 150GB is rather excessive and definitely not the norm.

I have several drives in my computer and each of them report an approximate 6-7% "loss" in space (this applies for drives that vary in size from 74GB to 250GB). So if we apply a 7% "loss" to this guy's 750GB hard drive, he should only lose 53GB, a far more reasonable number than 150GB.

After sifting a bit through reviews, it seems as though 698GB seems to be what everyone is getting when making one large partition. So my estimate of losing 7% wasn't far off.

Therefore, this definitely isn't a problem of base 10 versus base 2. Looks like the problem lies elsewhere.

Have you tried emptying the trash can? I know it sounds silly but it worked for me. Every time I'd delete stuff from my external drive I notice that the total capacity goes down. Then I realized that I would have to empty my trash can to free up that space again.