real disk space with the Compressed attribute on ntfs files?

[dabruro]

Is there any way to find out the true disk space used by files and folders when some of the files use ntfs compression (and perhaps sparse files too)?

GetFoldersize is very nice because it's the only similar utility I know that can avoid counting hardlinked files more than once. But then the sizes end up being inaccurate anyway because of compression. For example it says my files are taking up 610 GB on my 480 GB drive