It is not the formatting that "reduces" the raw size as they were that small to begin with.

There are two systems for calculating file system sizes. One is based on base-10 and the other is base-2.



HDD and SSD manufacturers uses base-10 when working with storage capacity numbers. To them, 120GB = 120,000,000,000 bytes. Windows and Linux however uses base-2 when working with data. To them, 120GiB = 120 x 2^30 bytes = 128,849,018,880 bytes. The OSX of Apple however changed their definition a few years ago to use base-10 when calculating file system sizes a few years back. To OSX, 120GB = 120,000,000,000 bytes, so it may report to you 120GB but you don't actually "regained" the "lost" capacity.

So where the 93% came from? 120,000,000,000 bytes / 128,849,018,880 bytes = 93% and this is before you even touched the device. This ratio is also non-linear, slowly changing as storage increases. 1000 bytes / 1024 bytes = 97.6% and 1TB / 1TiB = 90%. You will also lose a bit more after formatting for the actual formatted file system overheads.

Using this information, a 120GB SSD will have 120,000,000,000 bytes, which converts to 111.75GiB and that 111GiB is what your Windows OS will use when reporting to you. You can work out the values for the others, as this is only high school maths. However, there can be technical issues that alters the actual raw capacity. For example, OCZ's new SSDs based on the 25nm NAND Flash process will have an even smaller raw capacity.

so the raw capacity is around 90% ?

I have been thinking on replacing my 750 GB hdd for a 240 SSD mhhh performance wise look like a clear advantage to have a SDD however i have seen that many models across different brands simply fail over time which many me wonder. are SSD still very unreliable???

That percentage is variable, depending on the stated storage capacity. And not useful for most people, which is why that number rarely comes up in discussions. It's useful if you want to understand how things work and why your OS, with the exception of OSX, never reports 1TB or 120GB.

Most people don't even care about the actual raw capacity, all they needed to know is the number on the packaging and they will ignore the fact that Windows only reports 931.51GB available on their 1TB drive.

Now that you know the real reason why there is a "93%" difference, you can now return to your previously blissfully pleasant state of ignorance.

If reliability is a concern, buy Intel. Their G2 series had a failure rate of 0.4%, about 1 in 250 SSDs.

This post has been edited by everling: Apr 30 2011, 01:23 PM

Oh , then i should go with OCZ VERTEX 2 90GB for rm585 by lingloong

just jumped to the ssd bandwagon.

below is my team xtreem 60gb bought from seamonster for 2xx.



my mobo abit ip35-e dont support ahci, so scores might be lower than rated.

how fast is the boot up?

very fast compared to my old raptor 10k rpm or even current samsung f3 1tb.

cant wait to get mine

how about G3 series?

X GB/TB x 0.9313

so its around 93% raw capacity for all types of amount in ssd right?

Do the maths, 0.9313x
I own SSD

[attachmentid=2189546]

so far anybody using a PCIE , SSD.. rather than the normal sata one ?

80GB and u have 74GB ,thats pretty good eh?


ah , if , when i replace my laptop`s harddisk with ssd , that means i have to do a clean windows installation right?

and..how bout the SSD settings?

like the...err..AHCI mode or something...

For a single SSD, you should always run it in AHCI mode... Before you format & install a fresh copy of Windows, enable AHCI under your BIOS configuration first.

okay...then i have to do some research about it...cause i dont know anything bout my laptop`s bios :S

Official SSD-ed.

Guys, a quick question at the current market price of SSD, for example a Vertex 2 vs a Vertex 3

Isn't much more worth it to get 2x60Gb Vertex 2 in RAID0 configuration compared to buying a single piece of 120Gb Vertex 3? The Vertex 2 RAID0 should perform faster than Vertex 3 at a cheaper price right?

ayam jelly

People opt for vertex 3 coz of their laptops.

correct me if im wrong.