unallocated disk space???

[yuqisong]

I got my pc setup just now and my supposedly 120 GB SSD is only showing 110 GB in total????????? and checked my disk management and i see this unallocated space on my disks hmmmm... is there any way to restore my 120 GB SSD TY

[SorryBella]

1 minute ago, yuqisong said:

my supposedly 120 GB SSD is only showing 110 GB in total?????????

Overprovisioning. Its basically SSD's reserved position for data write and read to keep the wear in your SSD to a minimum.

 

 

And also windows 10 being loaded to your SSD doesnt help either.

[jaslion]

7 minutes ago, SorryClaire said:

Overprovisioning. Its basically SSD's reserved position for data write and read to keep the wear in your SSD to a minimum.

 

 

And also windows 10 being loaded to your SSD doesnt help either.

Mainly because windows does the 1024 KB is 1 MB thing whilst the manufacturers go 1000KB is 1MB so you lose a lot there.

[whispous]

8 minutes ago, SorryClaire said:

Overprovisioning. Its basically SSD's reserved position for data write and read to keep the wear in your SSD to a minimum.

 

 

And also windows 10 being loaded to your SSD doesnt help either.

This isn't overprovisioning.

[cacoe]

57 minutes ago, whispous said:

This isn't overprovisioning.

Agreed, but it will function as such effectivley.

 

The unused space is negligible though, I'd leave it.

[mariushm]

Your SSD has 120 GB = 120 , 000 , 000 ,000  Bytes

 

Windows uses multiples of 1024 when showing free disk space.

 

So that 120 GB is shown in Windows as 120,000,000,000  / (1024x1024)  = 114,490 MiB = 111.75 GIB

 

You can see in the picture:  

Your drive is reported as 111.77 GB, and there's a few partitions that don't have drive letters. 

You have a 508 MB recovery partition (if your windows crashes, the recovery process can copy files hidden then back to C: to repair them.

The first 100 MB probably contains the bootloader (a small program that's launched by the bios and in turn launches Windows) and probably the UEFI bios uses some of that 100 MB as temporary disk space if needed.

You have also 50+100+102 MB of unallocated disk space, those are basically empty areas not used by anything, "officially"

So you're left with 110.93 GB for C:  - that's 110.03  x 1024  (to get MB)  x 1024 (to get KB ) x 1024 (to get bytes )  = 119,110,180,536.32  bytes  or  119.11 GB out of 120 GB.

 

 

 

Hard drive / SSD manufacturers use multiples of 1000 when calculating sizes. 

 

The reason why Windows uses multiples of 1024 is historical, for backwards compatibility. 

When processors were much slower, and hard drives much smaller, there were various tricks used, and most of them are about powers of 2 - because processors can divide by 2 or multiples of 2 super fast. 

Dividing a number by 1000 was several times more processor intensive than dividing by 1024, because 1024 is 2¹⁰  so the programs could simply divide by 2 ten times, or shift the bits of a number to the right (one or two cpu cycles versus tens to hundreds to divide by 1000)

 

The file systems were designed so that the data was arranged in groups of 512 bytes for the same reason, and that's the smallest amount of data that can be read or written, and so a file will always take up multiples of that amount on the drive.... nowadays most drives still use 512 byte sectors or 4096 byte sectors... you can see that by looking at file properties on a small file, you'll see something like  700 bytes used, 1024 bytes used on disk. 

 

If it makes you feel better, the SSD actually has 128 GiB  worth of flash memory , as in 128 x 1024 x 1024 x 1024 , but that difference of  10 GB is hidden from the user and kept as spare space and write cache to extend the life of the SSD.