Hard drive values/sizes are different?

[fec32a4de]

I have two external HDDs both of the exact same model (HGST 1TB 7200RPM 2.5in)

These are my usual backups, and the HDDs are intended to be exact copies of each other,
however I noticed that while the number of files and folders is the same, total size of files and size on disk is the same,
when checking properties of the drives, it reports two different sizes and remaining disk space.

Considering the number of files and folders is the same, its probably nothing, but I couldn't help and notice
that remaining space is different.

What does this mean?

Thanks

 

[ThaiTaffy]

Take a look at them with disk manager you might find the one has some funky hidden partitions especially if it was plugged in during an os install, windows loves to dump junk on other drives when installing.

 

[newtekie1]

When you select all and then select properties, it doesn't select any hidden or system files that might be on the drive. Windows likes to put hidden/system files on every drive, and it can be different sizes. It will show up as used space, but you won't be able to see it.

I'd use TreeSize Free on each drive, run it as administrator, that will tell you everything that is on the drive and how much space it is using. So you can figure out what hidden file is taking up the extra space.

Take a look at them with disk manager you might find the one has some funky hidden partitions especially if it was plugged in during an os install, windows loves to dump junk on other drives when installing.

That really shouldn't cause this problem. The screenshot's he is showing read the partition properties, and it's saying the partitions on each drive are the same size.