I wanted to know what was the free available space in my internal HD (I actually have a SSD). In Finder, if I trust the Show Info information (right click or cmd+I on Macintosh HD icon in the Finder sidebar) I get a certain available space. Otherwise, if I just press the spacebar (quick insight), I get a different value, it seems that it's not updated. Finally, also Disk Utility reports a different value.
Why these three different values?
(this gap first appeared after upgrading to El Capitan and trash is already empty).
Available space displayed when clicking Show Info:
Available space displayed when pressing spacebar:
Available space displayed in Disk Utility:
Best Answer
I have a solution! You need a clean up spotlight index. Go to Preference - Spotlight - confidentiality. Press "+" and add whole disk to this. Check it in confidentiality list. After this - remove (by press -)
Turn off you mac. And boot with "safe mode" (by pressing shift + power button, until apple logo will be on display). Please be patient, safe mode loading not fast. And you may have some 'monitor artifacts'.
Check you disk space now. All good? If yes - just reboot again in normal mode.
p.s. this is solution, I got from Apple Care by phone.