Naked Science Forum

Non Life Sciences => Technology => Topic started by: krool1969 on 01/03/2013 21:51:18

Title: Why does my computer have less available memory than advertised?
Post by: krool1969 on 01/03/2013 21:51:18
When I bought my new laptop last year it was advertised as having a 300Gb hard drive. In fact it only has a 273Gb. A few weeks ago I spent $100 on a 1Tb (1000Gb) hard drive. When I hooked it up I found it is only 931Gb.

This seems to be a common practice with computers and computer assessors. Is there a good reason why we only get about 90% of the advertised memory?
Title: Re: Why am I shorted on my computer memory?
Post by: RD on 01/03/2013 23:35:47
It's a decimal / binary confusion thing ...

1 GB = 1 gigabyte = 1000000000 bytes

1 GiB= 1 gibibyte =  1073741824 bytes

so can appear to be short changed by 7%

https://en.wikipedia.org/wiki/GiB
Title: Re: Why am I shorted on my computer memory?
Post by: syhprum on 01/03/2013 23:44:37
When you set up new drives with an OS they make a special separate section for it.
Title: Re: Why am I shorted on my computer memory?
Post by: CliffordK on 02/03/2013 00:44:27
This has been an issue for quite some time
Drives are sold with unformatted capacity, even if they come preformatted.

You have both low level formatting, including the delineation of tracks and sectors (which you may not  be able to change), as well as high level formatting including the FAT table and basic directory structure.

Memory based devices (USB thumb drives & solid state drives) don't need the same low level formatting as standard disk drives, and the capacities should be more accurate.
Title: Re: Why does my computer have less available memory than advertised?
Post by: David Cooper on 02/03/2013 19:11:23
RD is correct. If you buy a 16GB flash drive and look at its actual size it'll be closer to 15GiB. This has nothing to do with partitions or formatting.

When Windows tells you how big a drive is, it uses GiB (but calls it GB - GB is ambiguous and can be used for both systems of counting).

When manufacturers sell drives, they always give you it in GB (and not GiB) - this is necessary because most consumers will automatically buy the drives with the bigger numbers attached to them without checking the small print.
Title: Re: Why does my computer have less available memory than advertised?
Post by: MrVat7 on 08/02/2014 02:59:06
They are cheaters , they should advertise the available memmory .
Title: Re: Why does my computer have less available memory than advertised?
Post by: McKay on 13/03/2014 07:18:55
No, no - the hard drive manufacturers are the ones geting it right. The OS is getting it wrong - showing GiB's as if they GB's. Mac OS, actually, made an update that shows it right now.. I hope microsoft does the same.