When a 1Tb disk is really 890Gb...

Over 100Gb lost - thats a lot!

That's the difference between 1TB and 1TiB. A TB is calculated as 1B*1000*1000*1000*1000, where a TiB is 1B*1024*1024*1024*1024.

OSes commonly measure in KiB/MiB/GiB/TiB and storage manufacturers measure in KB-TB. It's a bit of a con on the less techie people.

@sheeponmeth
IT people should know this

@Linux I agree, but not all IT people deal with storage first hand, so it can be a while before they come across it.

@sheeponmeth
but all IT people has bought a USB stick ;)

@Linux, you're taking away my ability to be nice. I'm trying to give them the benefit of the doubt, but you're ruining it all. I guess some people just aren't perceptive enough to notice.

I feel this is a con storage manufacturer do to sell hardrives.

it need index and other stuff

@sheeponmeth Even thats 931GB - wheres the other 40GB gone?

I've seen this for years (first noticed on a 5MB TRS-80 Winchester Disk! :)) but its obviously more noticeable on today's bigger drives!

@Linux we know and we still rant!

@spl0 Is it possibly to due formatting? And maybe a recovery partition is taking that up?

@sheeponmeth Could be formatting... dont think theres a recovery partition on there! This is on a NAS and being used as a cache, so not sure what its doing underneath tbh!

@spl0 Is it an HDD or SSD?

@sheeponmeth SDD that one!

@spl0 That's likely it, then, double check that it is in fact a 1TB and not a 960GB. Also, SSDs use additional space for internal management, so it could be that instead of providing additional nand for the overhead they just use part of the 1TB for it.

Also the file table/index of whatever file system youre using take up space too.