Question about HDDs/Also a question about Windows 7 and storage space

[Dubnoman]

I am planning on getting a new computer with an SSD for the OS and a 1 TB HDD for the bulk of information storage.

Now I'm curious to know some things. My current computer has a 750 GB HDD. However, ever since the time I first got it, when I would view the hard drive space indicator in Windows 7 (with the meter showing how much space there is taken up and how much is left), it would have some text under it, and it always has said "x amount of space free of 698 GB".

So what I'm curious about is how my 750 GB HDD has always only had 698 GB available. Was some automatically deducted from Windows 7 Home Edition (64-bit) being installed on the HDD as well as pre-installed software (I didn't build my own computer)? Thus, it has more than 698 GB of space but it was never written down as more than that when looking up the hard drive on my computer? Also, are 750 GB HDD ever truly with the full capacity? Are HDDs ever truly with the full capacity they are advertised with (I'm not talking about being off by a slight amount), or are HDDs off by several or more GBs? What about SSDs? Are they off by some significant amount?

Also, about my SSD that will have the OS on it, how much should I expect Windows 7 Home Premium (64-bit) to take up on the SSDs available space? I'll certainly have enough space for this version of Windows 7; I intend to buy a 256 GB SSD.

 

[DarkSable]

There are two parts to this question. The first is that Windows makes a hidden 10GB system boot partition. So that's 10 off.

The other portion of this is that hard drives are advertised with a little b: Gb rather than GB.

That means that because a GB is 1024 vs a Gb's 1000, a hard drive will never be as large as advertised when it's used in a computer. An ssd will have the same problem, but because it's a couple hundred GB rather than a thousand up, it won't be nearly as pronounced - my 128GB SSD shows up as 119 GB after the system partition.

 

[Someone Somewhere]

Actually, a Gb is one Gigabit; an eighth of the size of a GB. One GB is 10^9 Bytes, whereas windows measures data size in GiB which is 2^30 Bytes. It still states the value as being in GB though. There is a ~7% difference between them.

I don't know where you got the 10GB boot partion. I only see 100MB on my HDD.

 

[Dubnoman]

So I guess my 1 TB HDD will have about 925 to 930 GB. The difference is approximately 7%, so I'm looking at figures of 7% to 7.5%. It could always be just under 7%. So yeah, about 930 GB, give or take. I wish it was a full 1000 GB. 70 GB is a significant amount of space less than what the typical consumer is expecting when they go for something labeled "1 TB".