Why are disk drives never ever as huge as marketed?

From all the disk drives I have actually acquired, they never ever appear to be as huge as the promoted dimension; from 320 GB to 290 GB, from 500 GB to 450 GB, and so on. Exists a technological factor for this?

2019-05-07 08:27:20
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Answers: 4

The technological factor is that the hard drive suppliers market you abilities in statistics devices. So a GB = 1,000,000,000 bytes by the statistics system. Nonetheless, computer systems gauge the drive dimension in powers of 2. So 1GiB = 1,024 MiB, 1MiB = 1,024 KiB, etc What this suggests is that 1GiB = 1,073,741,824 bytes, a distinction of 73,741,824.

So when you install your 1GB (for instance) drive, the OS just sees 0.93 GiB, and also this is the source of the disparity.

(If you've never ever seen the acronym GiB prior to, it's a new symbols taken on to represent powers of 1024 in contrast to 1000. Nonetheless, most running systems will certainly report GiB as GB, perplexing this concern also better)

2019-05-09 02:59:16

They in fact generally are as huge as they are marketed, yet:

  1. They constantly (regarding I recognize) make use of 1000 as opposed to 1024 when doing B to KB and more.
  2. Some percentage of room is made use of by the documents system to track every little thing.

Might be various other factors also, yet those are the significant ones I find out about

2019-05-09 02:56:47

See this article for a description.

Primarily, there are 2 interpretations of a "gigabyte". One definition is that 1GB = 1024 3 bytes. This is the definition that the computer system records (for technological factors).

The various other definition (from SI devices) is that 1GB = 1000 3 bytes. This coincides as every various other statistics device (1 gigameter = 1000 3 meters).

Given that the statistics definition of a gigabyte is much less than what the computer system takes into consideration a gigabyte, hard drive suppliers make use of the statistics definition due to the fact that they can publish a bigger ability on package.

A percentage of room is additionally made use of by the documents system itself, yet a lot of the absent ability is from the definition of a gigabyte.

2019-05-09 01:46:14

When a drive supplier develops a 500 GB ability drive, it does have an ability of 500,000,000,000 bytes, and also they make certain mosting likely to market it thus. Computer systems, being binary tools, favor powers of 2, with a various set of prefixes, to make sure that is what they make use of for storage room dimension :

1 kibibyte = 2 ^ 10, 1 mebibyte = 2 ^ 20, 1 gibibyte = 2 ^ 30, etc

For instance, I have a 300 GB drive affixed to this equipment and also Windows presents the adhering to for the ability :

Capacity:          300,082,855,936     279 GB

300,082,855,936/ 2 ^ 30 = ~ 279. What it is in fact revealing you is the drive's dimension in gibi bytes, not giga bytes. So, it needs to read :

Capacity:          300,082,855,936     279 Gi

One could claim this is an imperfection in Windows, yet evidently there is no clear-cut criterion for storage space ability prefix definitions. Whole lots extra excellent details, consisting of an area on "Consumer complication", in this Wikipedia article.

2019-05-08 13:21:14