why we get less memory storage?

[viper08]

I have observed that we always get less storage than the stated capacity in HDD and memory sticks.

e.g I have following storages

Hard disks
Estimated Size Actual size
40GB 37.2GB
160GB 146.7GB
500GB 466.1GB

Pend Drives
Estimated Size Actual size
1GB 937MB
4GB 3.61GB
8GB 7.33GB

Above all are well known brands. I feel this was not the case before some years back.
Its something like you pay for 200 pages notebook which actually contains 182 pages only.

I understand that there will be some reserve space for firmware & other things but we are realy loosing too much.
What type of cost savings companies do in producing less virtual storage even if using more capacity hardware?

 

[goyal.sanchit]

According to the IBM Dictionary of computing, when used to describe disk storage capacity, a megabyte is 1,000,000 bytes in decimal notation. But when the term megabyte is used for real and virtual storage, and channel volume, 2 to the 20th power or 1,048,576 bytes is the appropriate notation. According to the Microsoft Press Computer Dictionary, a megabyte means either 1,000,000 bytes or 1,048,576 bytes.



When referring to a megabyte for disk storage, the hard drive manufacturers use the standard that a megabyte is 1,000,000 bytes. This means that when you buy an 80 Gigabyte Hard drive you will get a total of 80,000,000,000 bytes of available storage. This is where it gets confusing because Windows uses the 1,048,576 byte rule so when you look at the Windows drive properties an 80 Gigabyte drive will report a capacity of 74.56 Gigabytes and a 250 Gigabyte drive will only yield 232 Gigabytes of available storage space.



You can also see this as a marketing gimmick.

 

[gryph0n]

Also wanted to mention that each exponent/Level again uses the same rule.

So, your software will see a KB (KiloByte)=1024 bytes, MB(MegaBytes)=1024 KB, GB (GigaByte)=1024 MB, TB(TeraByte)=1024 GB.

Hard Disk, DVD, and CD ROM Manufacturers use "1000" everywhere. So when they say KB, they mean KB=1000 bytes, MB=1000 KB, GB=1000 MB, TB=1000 GB

So at each level, the difference grows larger. When a HDD vendor sells you a 500GB Harddisk, its capacity in terms of bytes = (1000 bytes x 1000 KB x 1000 MB x 500) = 500000000000 bytes or 500 billion bytes.

When your software sees the same capacity, it sees :
1. 488281250 KB (500000000000 / 1024)
2. 476837 MB (488281250 / 1024)
3. 465 GB (476837 / 1024)

Now, when you format the disk, the OS will allocate some space for holding the filesystem data/metadata. This should again reduce your actual usable memory by 1 or 2 GB more, but thats a small number compared to the con pulled off the manufacturers.

In the early days of computing, both manufacturers & software used the same notation of 1024 (2^10, since computers use binary notation). But soon the manufacturers realized they could con customers if they used notation of 1000 (10^3), claiming that SI units are based on powers of 10.

I believe that some time ago, there was a class action suit in the USA courts against HDD manufacturers for this falsely claimed capacity, and I think the manufacturers lost the case. After that, they have been careful to put disclamers on the products saying MB=Million Bytes, GB=Billion Bytes etc.

You see the same scenario with DVD ROMs and other media. DVD disks claim capacity of 4.7GB, where 4.7GB=4.7 Billion bytes, while the actual capacity is like 4.3 GB or something.

 

[gobble]

This is an old and well publicized issue worldwide. You take what the market gives or use a paper notepad. Things have not improved a decade after this issue was brought up.

Regards

 

[viper08]

Thanks a ton Guys for replies.
So it seems nothing will change in near future.

 

[entsurgeon]

well............. u also forgot another fact.... most storages have some amt of memory used up for installation/format software that eats up a fraction of the remaining capacity.
still, i suggest the thread be closed now. it ll only invite ranting now onwards