External Hard Drive Query? - DPChallenge Forums

Olympus 9-18mm f/4.0-5.6 M.Zuiko Digital ED

08/31/2006 06:07:35 AM · #1

Hey Guys

I get the feeling there is going to be a really simple explanation for this but not knowing a lot about technology I'm going to risk looking stupid to find out the answer!

I purchased a 160GB External Hard Drive yesterday. Set it up and its working perfectly. Only one small problem.

I haven't put anything on it yet but it tells me there is only 149GB capacity. So what happened to the other 11GB I paid for??

Like I say this is probably extremely simple and I may look daft but if you don't ask you don't know!

Message edited by author 2006-08-31 06:13:30.

jonr

Olympus OM-D E-M5

08/31/2006 06:13:09 AM · #2

I can think of few reasons:
1. Manufacturers are starting to use decimal KB instead of "real" KB. (1000 vs. 1024)
2. The OS needs to store information about the drive/files somewhere
3. Hidden partition

I'm betting on reason 1.

Tamron SP AF 28-75mm f/2.8 XR Di for Canon

08/31/2006 06:23:12 AM · #3

Originally posted by jonr:

I can think of few reasons:
1. Manufacturers are starting to use decimal KB instead of "real" KB. (1000 vs. 1024)

I'm betting on reason 1.

Thanks for your reply Jon. I wasn't lying when I said I am useless with technology! Probably gonna ask another silly question now but what does that mean? The manufacturer is allowed to advertise the product as having 160GB but they actually give you less, and thats ok?

Bobster

Canon EOS-20D

08/31/2006 07:00:08 AM · #4

its the same as Monitor Manufacturers advertising a 15" monitor and only giving you 14" ;)

the base in the Hard Drive world is 1,000kB = a megabyte and 1,000MB = a gigabyte etc. its all advertising stratergy..

its the same in the graphics world - AGPx1 was superseeded by AGPx2 when cards weren't even using the bandwidth that AGP1 gave, and then the same with AGPx4 when 2x wasn't even been used and now we're onto PCI-Express when again 8x wasn't being fully used! the only advantage PCI-Express gives is that you can have more than 1 card running at a speed greater than PCI..

and i believe they state that their 1GB = 1,000MB these days? - from a seagate package - 1 Capacity calculated as 1 Gbyte = 109 bytes.

and yes some of the HDD is gobbled up by the system when you format it as it has to set allocation unit size - you can loose or gain depending on what size you set (or if you let the system set it i believe its 64K)

Tamron SP AF 28-75mm f/2.8 XR Di for Canon

08/31/2006 07:05:18 AM · #5

Cheers for your reply Bob, I think I understand most of it ;o) I'll just have to be satisfied with the extra 149GB ;o)It's more than enough anyway lol

UNCLEBRO

Canon EOS-30D

08/31/2006 08:14:33 AM · #6

go and buy a piece of 2" x 4" and measure the actual size!
it's more like 1 1/2" x 3 1/2"

Canon EF 24-70mm f/2.8L USM

08/31/2006 08:26:19 AM · #7

Originally posted by UNCLEBRO:

go and buy a piece of 2" x 4" and measure the actual size!
it's more like 1 1/2" x 3 1/2"

Fair comment, as I said above I'm not all that techinical but 11GB seemed like a lot to lose that was all.

Kaveran

Canon EOS-50D

08/31/2006 10:06:10 AM · #8

Disk drives are divided into sectors or clusters and depending on the type of file system used on the disk the location and whats in these sectors/clusters is stored in a table(or multiple tables) on the disk. Think of these tables as an index in a book. The larger the drive and the more sectors the larger this index will be which takes away from the actual usable storage space.

violinist123

Canon EOS-6D

Canon EF 24-70mm f/2.8L USM

08/31/2006 10:17:44 AM · #9

Originally posted by talj:

Fair comment, as I said above I'm not all that techinical but 11GB seemed like a lot to lose that was all.

It seems like a lot because the small percentage you are losing is a large number when it's a percentage of a large drive. Disk mfg's have been doing this for 25 years, counting 1000 instead of 1024. It is unlikely they will ever change as marketing liars are marketing liars, however with the advent soon of consumer level terabyte drives perhaps people will start to bitch louder (or sue). Going to be hard to explain why your 1,000GB disk shows up in windows as 900GB or so.

Then again knowing microsoft they will collude and change how windows reports the space anyway.

ignite

Canon EOS-500D Rebel T1i

Canon EF 50mm f/1.8 II

08/31/2006 10:30:44 AM · #10

Every storage device needs some space to store the file allocation tables etc, same with FAT16, FAT32, or NTFS. You will always lose some space. I have a 512MB USB stick which is only useable for 470MB. My 200GB HD in external casing is only useable for around 170GB.