HD Question

[G.Kirby]

We have just had a new MacPro with 500Gb HD installed. But, usable space is only about 450Gb. I know that formatting requires space but 50Gb?

We have the same problem with a 200Gb MacBook Pro.

I feel like I have just bought a new car and found it has no steering wheel.

 

[zero2dash]

I have a 320g Seagate.
If the drive is empty - it registers as 298g.

It's the way hard drives are.
Chalk it up to that + the OS/app installation space taken up.

 

[balamw]

http://en.wikipedia.org/wiki/GiB

long standing issue with HDD vendors, they quote capacity in gigabytes, but the OS reports gibibytes which give you automatically a 8% reduction in space.

a 500 GB drive only has 465.6 GiB, which is usually what the OS reports.

500*1000*1000*1000 = 465.6*1024*1024*1024.

B

 

[G.Kirby]

I have a 320g Seagate.
If the drive is empty - it registers as 298g.

It's the way hard drives are.
Chalk it up to that + the OS/app installation space taken up.

Just been doing some maths. Looks like there is a consistent ratio to the size of HD and the amount of space after formatting. The magic number looks to be a ratio of 1.074.

So if you want to know how big a HD will be when formatted do this bit of maths.

Proposed HD size (eg 500Gb)
Divided by 1.074
Gives you your usable HD size (465.5Gb)

 

[G.Kirby]

http://en.wikipedia.org/wiki/GiB

long standing issue with HDD vendors, they quote capacity in gigabytes, but the OS reports gibibytes which give you automatically a 8% reduction in space.

a 500 GB drive only has 465.6 GiB, which is usually what the OS reports.

500*1000*1000*1000 = 465.6*1024*1024*1024.

B

Thanks, I think That's some proper Maths there lol

 

[balamw]

The magic number looks to be a ratio of 1.074.

1.0737=1.024*1.024*1.024 (see the article I linked above).

B