"Size" and "size on disk" show a very low number in 2012 Standard

I have a file server (now based on 2012) with TBs os data em milhlions of files

But the measurements are a little weird

In Server  2008 it´s fine, but in the 2012:

2008: Size, Size on disk e number os objects

2,95 TB (3.246.142.716.345 bytes)

3,00 TB (3.309.781.366.189 bytes)

1.735.570 Files, 239.194 Folders

2012 (it´s a replcia without the thumbs.db files, Size, Size on disk e number os objects)

2,95 TB (3.246.111.324.601 bytes)

>> - 24,4 GB (26.261.053.440 bytes) << --

1.735.569 Files, 239.194 Folders