New 200GB hard drive shows up as 184GB in My Computer

Alias_Omega

Why.?

Its brand new, i bought from eBay, opened the packet. Installed the software and its short.

Laptop had a 160GB hard drive in it before, was cheaper to buy the 200GB, HD was replaced as laptop was dropped by sister-in-law. £32 delivered.

Just finished install software and here we are..

Is there a problem, do i need to send it back.

pcombo

Well considering your operating system takes like 2gb or so. Plus any applications installed. And you never get the full capacity of a hard drive.

System

It's because hard drive manufacturers measure the capacity in true megabytes & gigabytes (divide by 10^6 or 10^12) and this is also the raw size. There is also a loss when formatted. A good example of this is a 3.5 floppy. This has a raw size of 2MB but formats to 1.44MB
MS programs divide by 1024 to report size but even that is not consistent.

This makes a 200GB disk only report 182 - 184 GB in Windows.

prowla

Computers think 1k is 1024, because it is the nearest power of 2 to 1000, whereas 1k to the rest of the world (be it bytes, grammes, metres, etc.) means 1000; this includes disk manufacturers.

So, if you buy a disk that is labelled 200 GB, the computer will tell you it is 186GB.

So the difference is around 14 GB. You haven't actually lost anything, it's just that your computer is telling you something different to your disk supplier.

Now, on top of that, each time you save a file oin a disk, it has to save the file's name, and information about where the chunks of file are located on the disk; this takes up disk space too, so you will find that some of your 186GB is taken by that.

On top of that, Windows may lose a bit of the end of the disk when you format it, and may also take some space for "swap".

And further, the disk's filesystem may only write data to disk in chunks of a certain size (eg. 1kB), which makes the disk activity simpler and faster. However, this does mean that if you create a very small file (eg. just the 5-letter word "hello"), it will use up 1kB (enough for 1000 letters) regardless. The effect of this is that lots of small files can eat up disk.

And finally, your computer's installation may have created a hidden "recovery" partition that can be used to restore a system if some things go wrong.

There are probably a few more reasons why you don't see 200GB, but that should cover the most of them.

456789

Excellent post prowla

Alias_Omega

I guess its just one of them things

Good news is that the laptop is working as advertised, just lost alot of files. The Sister-in-law has said she will pay the £32 (£31.99 for 200GB HD), so appart from the cracked hinge, its fixed.

Now to freeze the old hard drive to see if we can get anything from it, but i dont think so as its not spinning up.

Thanks all,

spud17

Laptop had a 160GB

Using the same calculation, the HD was 160GB, but in reality it was a fraction over 156GB.